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Free US shipping on orders $75+  ·  Every piece one of one  ·  Denver, Colorado
geoslut poster: Size matters. Sparkle matters more. Cactus quartz cluster from South Africa, amethyst points coated in tiny drusy crystals

hardcore minerals

Crystals and mineral specimens from Denver, Colorado

geoslut sells crystals and mineral specimens from Denver, Colorado, one piece at a time. Every specimen is one of one, labeled with its mineral and where it was mined, and photographed exactly as it ships.

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The first drop.

Mineral specimens for sale in the first drop

The mineral specimens for sale in the first drop are all one of one: when a piece sells it is gone, and the photo is the exact specimen you get.

geoslut poster: Creamy. Milky quartz cluster from San Juan County, Colorado, with stacked white points

Milky Quartz Cluster
San Juan County, Colorado

One of one  ·  Mohs 7  ·  Price at drop

geoslut poster: Smokin'. Rough. Raw. Always hard. Two elestial smoky quartz crystals from Minas Gerais, Brazil

Elestial Smoky Quartz
Minas Gerais, Brazil

One of one  ·  Mohs 7  ·  Price at drop

geoslut poster: Rock On. Raw blue kyanite cluster from Brazil with bladed crystals in pale matrix

Raw Kyanite Cluster
Brazil

One of one  ·  Mohs 4.5 to 7  ·  Price at drop

geoslut poster: Just the tip. Four quartz points with red lepidocrocite flecks gathered at one end

Lepidocrocite Crystal Points
Brazil, Madagascar, Spain, India

One of one  ·  Mohs 7  ·  Price at drop

geoslut poster: Meet Celestite. Pale sky blue celestite cluster with blocky, glassy crystals

Celestite Cluster
Locality at drop

One of one  ·  Mohs 3 to 3.5  ·  Price at drop

geoslut poster: Smoke Show! Smoky quartz cluster with dark brown, glassy points

Smoky Quartz Cluster
Locality at drop

One of one  ·  Mohs 7  ·  Price at drop

Know your rocks.

Types of crystals in the field guide

The field guide covers the types of crystals in the shop, science first: what each mineral is, where it is mined, how hard it is and how to spot a fake. Start with the A to Z or the Mohs hardness scale.

Smoky QuartzQuartz turned brown to black by natural radiation in the granite it grew in.Mohs 7Milky QuartzWhite quartz clouded by millions of tiny fluid bubbles, and the most common quartz there is.Mohs 7Spirit QuartzQuartz, usually amethyst, coated in a second growth of tiny crystals, mainly from South Africa.Mohs 7KyaniteBlue bladed aluminum silicate that is soft along its length and hard across it.Mohs 4.5 to 7CelestitePale blue strontium sulfate, soft and heavy, best known from Madagascar geodes; sunlight fades it.Mohs 3 to 3.5Lepidocrocite QuartzQuartz with red flakes and threads of lepidocrocite, an iron mineral, sealed inside.Mohs 7

No fakes.
No filler.

How to tell if a crystal is real

How to tell if a crystal is real comes down to knowing the five common tricks below. Every geoslut label names the mineral and the locality, so you never have to guess.

DyedAgate, howlite and quartz soaked in dye. Look for color pooled in cracks and blues or pinks too bright for nature.common
Heat treatedMost "citrine" is baked amethyst: burnt orange with white bases on the points.very common
IrradiatedClear quartz blasted black in a lab: an even, inky black, often over a milky white base.common
GlassOpalite and most cheap moldavite: round bubbles, swirls and no natural inclusions.common
CoatedAura quartz: real quartz with a metal film bonded on in a vacuum chamber. It can scratch off.labeled here

Read the real or fake guide

Mined in
Colorado.

Colorado minerals from a Denver shop

Colorado minerals anchor the geoslut cabinet, starting with milky quartz from San Juan County. The Colorado guides cover where to dig, the Denver Gem and Mineral Show and the state's classic finds.

Colorado minerals

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