Amethyst: Geology, History, and How This Purple Crystal Forms

Amethyst is quite possibly the most instantly recognizable and widely loved gemstone on this planet.  With its rich purple hues, it is a really beautiful rock.  

It also has a long history across cultures though centuries of myths and lore.  This crystal weaves together geology, art, and human belief.   Whether you know it as February's birthstone in jewelry, a meditation crystal, or simply a beautiful rock specimen or gem, amethyst has a surprisingly deep story to tell.

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What Is Amethyst?

Amethyst is a variety of quartz, one of the most abundant minerals on Earth. What makes amethyst special is its purple coloration, which can range from pale lavender to deep, velvety violet.

Chemically speaking, amethyst is silicon dioxide (SiO₂). Its purple color comes from trace amounts of iron in the crystal structure, combined with natural radiation from surrounding rocks over millions of years. 

Amethyst Crystal Specimen

The Geology: How Amethyst Forms

Amethyst most commonly forms inside geodes or within veins of volcanic rock.

The formation process looks like this:

• Volcanic activity creates gas pockets in cooling lava

• Mineral-rich groundwater flows into these cavities

• Over long periods of time, quartz crystals slowly grow

• Iron impurities and radiation interact to produce purple coloration

Some amethyst geodes grow to extraordinary sizes and can weigh several tons, forming cathedral-like interiors lined with crystals.

Notable Amethyst Locations

• Brazil for large geodes and widespread deposits

• Uruguay for deep, richly saturated purple crystals

• Zambia for high-quality stones with excellent clarity

• Russia for historically prized royal specimens

• United States, including Arizona and North Carolina

Amethyst Crystal Points and Geode

Amethyst through History

Amethyst has been valued for thousands of years, and not just for its beauty.

Ancient Greece

The name amethyst comes from the Greek word amethystos, meaning “not intoxicated.” Ancient Greeks believed the stone protected against drunkenness and mental clouding. Amethyst was often carved into drinking cups and worn as amulets.  You can still find carved amethyst cups here!

Medieval Europe

During the Middle Ages, amethyst became associated with humility, spiritual clarity, and wisdom. It was commonly worn by clergy, especially bishops, and remains a traditional stone in ecclesiastical rings.

Royal Symbolism

Before large deposits were discovered in South America in the 1700s, amethyst was rare and considered a precious gemstone, valued alongside diamonds, rubies, and emeralds. Many royal crowns and regalia feature amethyst as a symbol of balanced power and clear judgment.

Amethyst Gemstone Heart

Symbolism & Meaning

Across many cultures, amethyst has been linked to:

• Calm and emotional balance

• Protection and clarity of thought

• Balance between mind and emotion

• Reflection and inner awareness

Today, it’s often associated with meditation and stress relief, not because it magically solves problems, but because humans have long tied meaning to beauty and intention.

Fun Facts About Amethyst

• Prolonged exposure to strong sunlight can cause amethyst to fade over time

• When heated, amethyst can turn yellow and become citrine. Many citrine stones on the market began as amethyst

• Despite its regal appearance, amethyst shares the same base structure as common quartz found in sand

• Amethyst is the traditional birthstone for February

• It ranks 7 on the Mohs hardness scale, making it suitable for jewelry and long-term display

Handmade Amethyst Necklace

Amethyst Today

Amethyst is a favorite among rock shop visitors because it appeals to both serious collectors and casual admirers. It comes in many forms, including:

• Natural crystal clusters

• Cut and polished points

• Large geodes and cathedral pieces

• Tumbled stones

• Jewelry-grade crystals for engagement rings, birthstone pendants, bracelets, and more.  

Each piece is unique, shaped entirely by natural processes. Amethyst offers a perfect balance of beauty, durability, affordability, and geological interest. It is often one of the first minerals that sparks curiosity and a lifelong interest in rocks and crystals.

When selecting raw amethyst, look for good crystal formation, pleasing color, and minimal damage to crystal points. Keeping specimens out of prolonged direct sunlight will help preserve their color.

When shopping for amethyst jewelry, this collection offers something for every budget.  Or if you're looking for something more unique and handmade, Etsy is a great place to find it.  

Why Amethyst Endures

Amethyst has remained popular for centuries because it combines natural beauty with a rich human story. It is formed through slow geological processes, treasured by ancient civilizations, and still admired today by collectors, jewelers, and rock enthusiasts alike.

Whether displayed as a dramatic geode or held as a single crystal, amethyst continues to remind us why people have always been drawn to the natural world.

Earth in Motion: The Hidden Power of Plate Tectonics

When you look at an old history map of the world and compare it to a new one, the continents seem fixed and permanent. But the truth is, Earth’s surface is always changing and moving. Mountains rise, oceans open and close, and continents slooooowly drift across the planet, all because of a process called plate tectonics.

Plate tectonics is the scientific theory that explains how the rigid outer layer of our planet shifts and changes over time. The ground usually feels solid beneath our feet, unless we're sliding down a talus slope we probably shouldn't have climbed in the first place...  However, it is part of a dynamic system powered by heat from Earth’s interior. The slow motion of tectonic plates shapes continents, carves ocean basins, forms mountains, and drives earthquakes and volcanoes.

Understanding plate tectonics gives us a way to make sense of Earth’s most dramatic features and the processes that continue to reshape our planet every day.

The Lithosphere and Tectonic Plates

Earth’s outer shell, called the lithosphere, includes the crust and the uppermost mantle. It’s broken into large, rigid pieces called tectonic plates. These plates float on the softer, hotter asthenosphere below, which can slowly flow.

Because of this flow, plates are constantly moving, even if it’s only a few centimeters per year. Over millions of years, these small movements create major changes on Earth’s surface. Every place on the planet sits on a plate that has been moving and interacting with other plates for billions of years.

Why Plates Move

So what makes plates move? The answer is heat from inside Earth. This heat drives mantle convection, where hot material rises and cooler material sinks, creating slow circulation in the mantle.

Gravity helps too, by influencing these:

• Ridge push: plates slide away from elevated mid-ocean ridges.

• Slab pull: dense, sinking plates pull the rest of the plate along.

Together, these forces keep Earth’s surface in constant motion.

Plate Boundaries and Geological Activity

Most tectonic activity happens where plates meet, at what geologists call plate boundaries. There are three main types of boundaries, and each creates different geological features.

Convergent Boundaries

At convergent boundaries, plates move toward each other. When an oceanic plate meets a continental plate, the denser oceanic plate sinks below the continent in a process called subduction. This forms deep-sea trenches, volcanic arcs, and strong earthquakes.

When two continental plates collide, they push against each other and the crust thickens, forming mountain ranges like the Himalayas.

Divergent Boundaries

At divergent boundaries, plates move apart. Magma rises from below, cools, and forms new oceanic crust. This process, called seafloor spreading, happens mainly along mid-ocean ridges and slowly reshapes the ocean floor.

Transform Boundaries

At transform boundaries, plates slide past one another along strike-slip faults. No crust is created or destroyed, but stress builds up and is released as earthquakes.

Why Plate Tectonics Matters

Plate tectonics explains why earthquakes, volcanoes, and mountains happen where they do. It also shapes continents, ocean basins, and sedimentary basins over millions of years.

Plate movement even affects the carbon cycle, which helps regulate Earth’s climate, and influences the distribution of natural resources. Without plate tectonics, Earth would be geologically quiet and far less capable of supporting life.

A Planet That Never Stops Moving

Even though plates move slowly, their motion is more or less constant. Over geologic time, small shifts become major changes. Plate tectonics shows that Earth is not a static planet. Its surface is alive, constantly evolving, and still being shaped by internal forces today.

If you're an avid hiker or off-road enthusiast, learn how to recognize and stay safe from some of the hazards due to ongoing movement in the earth that you might encounter on an adventure.

Natural Hazards Every Hiker Should Know (A Geology Based Safety Guide)

Geology Isn’t Just About Cool Rocks. It Can Keep You Alive Outdoors.

Understanding real-world geology can make your time outdoors more meaningful and, in some cases, far safer. It helps you read the landscape, understand the forces that shaped it, and recognize situations that could quietly become dangerous.

Chances are, you will never encounter most of the hazards discussed here on an average hike or outdoor trip, and that is a good thing. The goal is not fear, but awareness. Knowing what could happen allows you to avoid putting yourself in risky situations in the first place. And if you do end up in the wrong place at the wrong time, being prepared can make all the difference.

Geology is the study of Earth’s processes over immense spans of time, but those processes are still at work today. Mountains continue to break apart, deserts still flood, glaciers keep moving, and faults still slip. When we hike, drive, or dig in wild places, we are stepping into systems that are active and constantly changing.

Understanding geology helps you recognize when a landscape is relatively stable and when it may be under stress. Many outdoor accidents follow patterns that geology can help explain after the fact. Learning those patterns gives us better tools to make informed decisions in the field.

Let’s look at some outdoor hazards through a geological lens, and how a little knowledge can help you explore wild places more safely.

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Flash Floods. Ancient Waterways That Still Work. Water That Moves Faster Than You.

Desert landscapes often appear dry and lifeless, but many of their most stunning features have been shaped by water. Sandstone, shale, and volcanic rock commonly form impermeable layers that prevent rain from soaking into the ground. Instead, water runs across the surface, collecting into drainage basins that feed washes, arroyos, and slot canyons.

Over time, the washes, arroyos, and slot canyons become wider or deeper, and may seem like they exist precisely to funnel sudden floods.These channels flood repeatedly over geologic time. When storms occur upstream, water accelerates downhill, sometimes traveling many miles before reaching narrow canyons. The constricted walls increase flow speed and depth, turning shallow runoff into a violent surge.

One well known place this mechanism has led to fatal floods is Antelope Canyon, Arizona.  This specific location is not more dangerous than other slot canyons.  The same combination of geology and weather occurs throughout many desert areas, especially during thunderstorms that pop up in the summer in the southwestern USA.  Distant storms sent walls of water through a narrow sandstone slot with little warning. Clear skies overhead offered no protection because the geology had already built the perfect flood channel.

For off-roaders, dry washes are tempting travel corridors. For rockhounds, flood channels often expose fresh material. In both cases, the geology tells the same story. If water carved the path, water will return.

Quick Geology Facts to Remember and Research:
If you didn't have time to read the entire section or want to research on your own, remember this.  Impermeable bedrock, watershed geometry, gradient, and channel constriction control flood behavior. Desert floods are fast because the ground cannot absorb water and the channels are steep and narrow.

Gear that helps:

• Weather radio to monitor storms in nearby watersheds

• Waterproof backpack to keep gear dry if you need to move fast

• Emergency satellite communicator in case you get trapped or need rescue (may require subscription service)

Rockfalls and Landslides. The Slow Failure of Stone.  (Even Mountains Fall Down.)

Rock appears permanent, but most cliffs are slowly being torn apart. Physical weathering, especially freeze and thaw cycles, forces water into fractures where it expands and widens cracks. Chemical weathering weakens mineral bonds, while gravity applies constant stress to slopes.  These processes attack all rock types, big and small, sedimentary, igneous, and metamorphic.  

Over time, rock masses become fractured internally. Failure does not require an earthquake or storm. Eventually, gravity overcomes friction and cohesion, and rock detaches.

Fatal rockfalls in popular places like Yosemite National Park have occurred, where large granite slabs separated along exfoliation joints and fell without warning. The cliffs looked stable because the fractures were internal, not visible from the surface.

Rockhounds increase risk when digging into weathered slopes or beneath overhangs, removing material that was providing support. Off-roaders may stop beneath road cuts where blasting and erosion have already compromised stability.

Quick Geology Facts to Remember and Research:
If you didn't have time to read the entire section or want to research on your own, remember this.  Rock type, joint orientation, fracture density, slope angle, and weathering history determine stability. Granite exfoliates, sedimentary rock fails along bedding planes, and volcanic rock often breaks along cooling joints.

Gear that helps:

• Climbing helmet or mining hard hat to protect against falling debris

• Trekking poles to test unstable ground and improve balance

• Durable hiking boots for men or women for traction on loose slopes

Volcanic Hazards. Landscapes Ready to Explode... or Collapse.

Volcanic terrain is shaped by magma moving beneath the surface, sometimes without eruption. As magma rises, it fractures surrounding rock, releases gas, and heats groundwater. These processes weaken rock and create unstable ground.

The 1980 Mount St. Helens eruption demonstrated the real and dangerous hazards of a volcano.  A massive landslide removed the mountain’s north flank, releasing pressure and triggering a lateral blast. The most destructive force was not lava, but rapidly expanding gas and debris.

Ash fall from volcanic eruptions can collapse roofs, reduce visibility, and turn soil into slick mud. 

Altered volcanic rock may appear mineral-rich and great for rockhounding or exploring, but is sometimes structurally weak or even extremely hot beneath the surface, especially in places with hot springs and geysers. 

Even if the area is not part of a currently active volcanic system, hazards can still be present.  In places where volcanic activity has occurred, lava fields are full of jagged, sharp rock that can damage footwear and even rugged off-road vehicle tires.  Lava tubes are fun to traverse, but crawling around in dark confined areas with thin ground and jagged surfaces requires some precautions.

Quick Geology Facts to Remember and Research:
If you didn't have time to read the entire section or want to research on your own, remember this.  Gas pressure, magma movement, hydrothermal alteration, and ash deposition create hazards far beyond lava flows. Volcanic rock is often fractured, vesicular, sharp, and mechanically weak.

Gear that helps:

• Durable clothing if you’re exploring young sharp volcanic terrain

• Rugged sunglasses to protect eyes from wind-blown dust and debris

• Quality tires for your off-road rig

• Packable headlamp to inspect terrain or see while changing a tire in the dark

Earthquakes. When Earth Gets Too Stressed.

Earthquakes occur when tectonic stress builds along faults faster than it can be released. When friction is overcome, rock slips suddenly, releasing energy that fractures ground and destabilizes slopes.

During events like the 2019 Ridgecrest earthquakes in California, desert terrain becomes permanently altered. Fault scarps crossed roads, boulders fell from hillsides, and ground cracks opened in previously stable areas. These changes occurred far from large cities, so rescue and repairs were delayed.

Earthquakes often trigger secondary hazards. Rockfalls, landslides, and ground liquefaction may occur minutes or even hours after the initial shaking.

For off-roaders, this means familiar trails may no longer be familiar in places. They may have surprise new obstacles or dangerous impassable areas, especially on shelf roads. 

If you're out looking for rocks in areas with many active faults, be aware that fresh fractures may still be shifting.

Quick Geology Facts to Remember and Research:
If you didn't have time to read the entire section or want to research on your own, remember this. Fault geometry, rock strength, depth of rupture, and local geology control earthquake damage. Shallow quakes produce stronger surface effects and destabilize slopes.

Gear that helps:

• Basic first aid kit for minor injuries, cuts, and scrapes

• Tow strap for when you attempt that new obstacle and it was uh, a bit too much

• Portable power bank to keep communication devices charged

Glacial and Alpine Hazards. Ice Is Not Solid Ground.

Glaciers behave like slow-moving rivers of ice. They fracture as they flow over uneven terrain, creating crevasses and unstable ice towers called seracs. Moraines consist of loose debris dumped by melting ice and are rarely compacted.

In the Mont Blanc massif, warming temperatures have increased glacier movement and collapse, causing fatal accidents even in established climbing zones. Ice stability can change dramatically over the course of a single day.

In less dramatic climates, rockhounds often explore newly exposed rock as snow and ice melts, but this terrain is not always what it seems. Loose debris, thin ice on winter trails over hidden lakes and rivers, and meltwater make these areas unpredictable.

Quick Geology Facts to Remember and Research:
If you didn't have time to read the entire section or want to research on your own, remember this. Ice flow, temperature gradients, and seasonal melt cycles control glaciers and ground stability. Recently deglaciated terrain lacks soil cohesion and structural integrity. Thin ice can hide deep or fast flowing water.

Gear that helps:

• Crampons for traction on ice

• Ice axe for use on steep slopes

• GPS device to stay on trails and help avoid unsafe terrain

Hidden Ground Hazards.  A Note on Old Mines.

Old mine workings are enticing.  The history, the adventure... the rocks!   However, they can be extremely dangerous.  This is the part where it's obligatory to say, "Stay out of abandoned mines!"  OK? OK. 

Mining introduces artificial voids into often already fractured rock.  Over time, wooden supports rot, roofs collapse, and toxic gases accumulate. 

Clay-rich soils swell when wet and shrink when dry, causing ground movement. Caliche other brittle layers can collapse when undercut. These hazards are especially dangerous for rockhounds digging in mineralized areas and off-roaders traveling in remote terrain.  Mine tunnels can extend unseen far from mine entrances under trails and roads.  

Trespassing on private land to explore an old mine site may also get the attention of the owner, who may defend their property as they see fit.  Always get permission from the owner before exploring anything at all that's located on private property.  Not only is it safer, it's the right thing to do.  

Quick Geology Facts to Remember and Research:  

If you didn't have time to read the entire section or want to research on your own, remember this.  Soil composition, moisture content, and subsurface voids control ground stability. Human alteration often accelerates natural failure.

Gear that helps:

• Sturdy boots for men or women for unstable terrain

• Hardhat with headlamp for exploring low-light areas safely 

• Map with lots of places to adventure that are NOT abandoned mine sites

• This Rockhounding Atlas - for finding places to collect rocks (with 553 verified GPS sites)

How Geologists Read Warning Signs

Geologists look for evidence of active processes. Fresh fractures, angular debris, tilted trees, sagging ground, altered drainage, and unusual odors all indicate instability. Landscapes reveal their history to those who know how to read it.

If the terrain shows signs of recent movement, it is most likely still moving.

Adventure Smarter, Not Braver

Every hazard discussed here follows predictable geological rules that are still in effect today. The same forces that shaped these landscapes continue to shape them now.

Whether hiking, off-roading, or rockhounding, geological awareness allows you to anticipate danger rather than react to it.

The ground beneath you is never truly still. Learn to understand it, and you will travel farther and safer.

Explore boldly, but think like a geologist.

Ready to head out and need some affordable camping gear that's still actually durable?  Check out my favorite items here.

If you've found some cool rocks on one of your adventures, and it's a little tricky to figure out what they are, check out this post on how to identify rocks at home.

Just want to look at pretty rocks for a while?  Check out these two pages on Etsy:  

Grumbly Tumbleweed

Desert Snail Minerals

This site will help you find local rock and mineral shows anywhere in the USA or Canada!

https://xpopress.com/

 

Campfire Nachos: An Awesome Outdoor Recipe for Cooking while Camping

Campfire Nachos with Jalapeños

Campfire Nachos with Sour Cream

Cooking over a campfire is one of those things that sounds very rustic and wholesome, until you’re crouched near the fire wondering if your food is actually cooking or just… thinking about cooking. There’s smoke in your eyes, you can't reach your chair, and someone keeps poking the fire with a stick like that will solve everything. 

Still, campfire cooking has a certain charm.  When it works, you feel wildly accomplished for doing something humans have done forever.  It's fun, magical, and memorable. 

It's extra memorable when the marshmallow you're roasting catches on fire, so you shake it violently to put the flames out... and it ends up stuck to your back.  (Yes, that really happened.)

Anyway, we're here for the campfire nachos, not my sticky misadventures.  

Are nachos meant to be made outdoors? Not especially. Do they still somehow work? Absolutely, and they're surprisingly easy!  

They're messy, melty, and endlessly customizable, which makes them the perfect warm comfort food to share after a long day hiking or looking for rocks.  It’s probably dark out, and no one will be able to tell whether that meat is fully cooked or not, so maybe save the steak for another night.

Nachos are ideal because you can eat them straight from the pan, semi-warm, while standing around the fire, and pretend that was the plan all along.

As long as you have a vague idea of what to put on them and remembered most of the ingredients (the chips are the most important part), all you really need is a cast iron skillet, a fire grate, and a can opener. If you forget the can opener, a rock hammer and a screwdriver technically work… but I don’t recommend this method.

Start by separating your ingredients into two categories: things that should be warm, and things that shouldn’t. My “warm” category usually includes the chips (the yellow corn ones are my favorite), plus some combination of black or refried beans, pre-cooked hamburger crumbles, and grated cheese.

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Coat the cast iron skillet with oil.  Vegetable oil works the best.  Olive oil has too low of a smoke point and tends to burn.  Spread the chips evenly in the pan, then add the beans and/or meat.

Sprinkle grated cheese over the top.  You can never have too much cheese!  I usually use a Mexican cheese blend, but cheddar works just as well.   

Once everything that needs to be warm is in the pan, cover it with foil and set it on the campfire grate. Check it occasionally until the cheese melts… or until you get hungry, lose faith in your fire cooking abilities, and decide to eat it warm-ish. It is better if you wait, though, I promise. Toss another log on the fire and listen to your friend’s off-key yodeling for a bit. Just keep the fire fairly small; burnt tortilla chips aren’t great.

I tried using fresh jalapeños once, instead of the kind that come in a jar, and added them with the warm ingredients. It didn't work nearly as well.  The jar jalapeños were way better, less crunchy and way less seedy.  

While the nachos are heating up, prep the cold toppings. I usually bring lettuce, tomato, jarred jalapeños, fresh cilantro, hot sauce, and more shredded cheese. There’s a dedicated camping kitchen knife that lives with the rest of the gear, but a pocket knife works fine too, as long as it gets wiped on someone’s pants leg first.

Set the hot cast iron skillet on a towel, add the cold toppings, scoop on some sour cream, and grab a fork if you’re feeling fancy. If not, just dig in and enjoy!

Here's the recipe:

Is This Calcite or Quartz? How to Tell the Difference

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I don't know how many times I've been in the field trying to figure out which way is north, how I will fit that gigantic rock in my pack, how to put that gigantic rock in someone else's pack, or something equally as silly, when someone picks up a rock and says, "Hey, look at this calcite!"  

I reply with, "That's quartz."

One of us is inevitably wrong, but how do we solve this dilemma?

Quartz and calcite are two common minerals that can look similar, but they have distinct properties that make them easy to tell apart. Here are the key differences:

1.  Reaction to Acid

My first reaction is to pull out my acid. Hydrochloric acid, that is.  Calcite reacts with hydrochloric acid (HCl), muriatic acid (diluted, less pure HCl) or even vinegar, fizzing or bubbling as it releases CO₂.

Quartz does not react to acid at all.

I purchased these squeeze dropper bottles in 2019 (that's like 7 years ago now, yikes!) to carry a small bottle of acid into the field with me.  I'm still using the first one. It has never leaked in my rock bag... yet... and I'm pretty rough with it, since I usually forget it's there until there is a quartz / calcite fiasco.  

30 mL Squeezable Eyedropper Bottle with Cap

2. Hardness (Scratch Test)

Quartz (7 on the Mohs scale) is much harder than calcite (3 on the Mohs scale). If I don't have my rock bag, I pull out my trusty Leatherman Skeletool and run the blade against a piece of the rock in question.  A steel knife will easily scratch calcite, but it will not scratch quartz.  

If there is any glass laying around that is not your windshield or your eyeglasses, you can see if the rock scratches it.  Quartz can scratch glass, while calcite cannot.

3. Cleavage and Fracture

When all else fails, hit it with your rock hammer!  Calcite has perfect rhombohedral cleavage, meaning it breaks into three planes ( not necessarily 3 pieces) at angles that aren’t 90 degrees.

Quartz has no cleavage and instead exhibits conchoidal fracture, meaning it breaks in curved, shell-like patterns.

4. Crystal Shape

This should probably be the first step, but if you're like me, you probably don't do things in order, or the smart way.  (The hard way is the only way, right?)  Look at the rock! 

If you see any well formed crystals, look at the shape.  Quartz typically forms six-sided (hexagonal) crystals with pointed terminations.  Calcite often forms rhombohedral or scalenohedral (dog-tooth) crystals.

5. Transparency and Luster

Again, look at the rock.  Like really study it... 

Both minerals can be transparent to opaque, but calcite often has a pearly to vitreous (glassy) luster, while quartz is usually just vitreous.

Some clear calcite specimens exhibit double refraction, meaning objects viewed through them may appear doubled. Quartz does not show this effect.

6. Color and Varieties

This one is low on the list, because color seems like the most obvious thing to look at, but it never actually helps me.  If I'm confused about a rock being quartz or calcite, it's probably white or clear-ish.  

Quartz comes in many colors (clear, white, purple, pink, yellow etc.), but so does calcite (clear, white, yellow, green, blue, red, or brown), and vary rarely am I finding colorful varieties of either one.  If you are, please take me with you on your next adventure!

7. UV Reactivity

Does it glow under a UV flashlight?  Not all calcite will fluoresce, but some does, and though it can be many colors due to impurities, it will usually be a red or orange color.  

Calcite glowing orange under 365 nm UV light

Quick Field Test Summary

• Test with acid: Calcite fizzes; quartz doesn't.

• Check hardness: Quartz won’t scratch easily, while calcite scratches with a knife.

• Look at how it breaks: Calcite cleaves into angled planes; quartz breaks with curved, shell-like fractures.

• Examine crystal shape: Quartz forms hexagonal points; calcite forms rhombs or dog-tooth crystals.

• Watch for optical clues: Double refraction or pearly luster points to calcite.

• Don’t rely on color alone: Both minerals come in many shades.

• Use UV light if you have it: Some calcite fluoresces; quartz usually doesn’t.

By using these tests, you can confidently distinguish between quartz and calcite!