Herkimer Diamonds
Herkimer Diamonds Doubly-terminated quartz crystals used as specimens and gems.
The Acid Test
The Acid Test Geologists use dilute hydrochloric acid to identify carbonate minerals.
Tumbled Stones
Tumbled Stones are rocks that have been rounded, smoothed and polished in a rock tumbler.
Zircon
Zircon is the primary ore of zirconium and a gemstone that is available in many colors.
Fool*s Gold
Fool*s Gold is a name used for pyrite when its brassy color fools people looking for gold.
Kyanite
Kyanite is a metamorphic mineral used to make porcelain, abrasive products and gems.
Rock Tumbling
Rock Tumblers - enable you to convert rocks and minerals into beautiful gems.
Rhodochrosite
Rhodochrosite - a manganese mineral used as an ore, a pink gem and an ornamental stone.
Topaz
Topaz is a mineral best known as a durable gemstone and its use in Mohs Hardness Scale.
Quartz
Quartz is the most abundant mineral in the crust. It has many useful properties.
Rhodonite
Rhodonite - a manganese silicate used as a minor ore of manganese and as a gemstone.
What Are Minerals?
Minerals are the building blocks of our society. We use items made with them every day.
Copper
Copper is a metal used in coins, electronics, pipes, wiring, motors, alloys and many other products.
Cinnabar
Cinnabar - the only important ore of mercury. Used in pigments until its toxicity was realized.
Grape Agate
Grape Agate is a popular mineral specimen with the color and the shape of a bunch of grapes.
Tourmaline
Tourmaline - the most colorful mineral and natural gem material on Earth.
Benitoite
What Is Benitoite? A rare mineral and the State Gem of California - USGS report from 1911.
Mineral Hardness
Mohs Hardness Scale is a set of reference minerals used for classroom hardness testing.
Diopside
Diopside - Gem material, ornamental stone, diamond indicator, industrial mineral.
Garnet
Garnet is best known as a red gemstone. It occurs in any color and has many industrial uses.
Diamond: The Mineral
Diamond is a mineral with unique properties and many gem and industrial uses!
Hemimorphite
Hemimorphite is an ore of zinc that can often be cut into gems with spectacular blue color.
Uses of Gold
Gold has unique properties that make it one of the most useful minerals.
Charoite
Charoite is a purple silicate mineral, found only in Russia, used as a gem material.
Vanadinite
Vanadinite is an important ore of vanadium and a minor source of lead.
Smithsonite
Smithsonite is a zinc carbonate mineral, an ore of zinc, and a minor gemstone.
Sugilite
Sugilite is a rare mineral and a gemstone best known for its vibrant pink to purple color.
Corundum
Corundum is the third hardest mineral. It is also the mineral of ruby and sapphire.
Calcite
Calcite is a carbonate mineral with industrial, agricultural, medical and many other uses.
Mineral Luster
What Is Luster? Luster is the light-reflecting characteristics of a mineral specimen.
Olivine
Olivine - Abundant in Earth*s mantle. A constituent of meteorites. The gem peridot.
Gifts That Rock
Gifts That Rock - What are the most popular gift items in the Geology.com store?
Azurite
Azurite - Used as an ore of copper, a pigment, ornamental stone and gem material.
Serpentine
Serpentine - metamorphic rocks used in construction, architecture and lapidary work.
Magnesite
Magnesite is a carbonate mineral used for chemicals, fire bricks, magnesium metal and more.
Streak Test
The Streak Test is a method to determine the color of a mineral in powdered form.
Andalusite
Andalusite is a metamorphic mineral and a strongly pleochroic gem material.
Variscite
Variscite is a yellowish green to bluish green mineral. It is similar to turquoise and cut as a gem.
Rutile
Rutile - an ore of titanium; a source of titanium oxide; causes stars and eyes in gems.
Lepidolite
Lepidolite is a pink to purple mica used as an ore of lithium and as a gem material.
Spodumene
Spodumene is a pegmatite mineral, an ore of lithium and sometimes a gemstone.
Ilmenite
Ilmenite - The primary ore of titanium and source of most titanium dioxide.
Molybdenite
Molybdenite is the primary ore of molybdenum which is used in superalloys and as a lubricant.
Crystal Habit
Crystal Habit is the external shape displayed by a crystal or an aggregate of crystals.
Hematite
Hematite - the most important source of iron ore and mineral pigment since prehistory.
Rare Earth Elements
Rare Earth Elements are used in cell phones, DVDs, batteries, magnets & many other products.
Uses of Silver
Uses of Silver Most people think of jewelry and coins, but silver\'s primary use is industrial.
Chalcopyrite
Chalcopyrite - The most important ore of copper for over five thousand years.
Mineraloids
Mineraloids are amorphous naturally-occurring inorganic solids that lack crystallinity.
Hand Lens
Hand Lens A 10-power folding magnifier in a metal case. A frequently used lab and field tool.
Hardness Picks
Hardness Picks - Test for hardness with precise and easy-to-use hardness picks.
Olivine Rain
Olivine Rain Spitzer Telescope discovered a rain of olivine crystals on protostar HOPS-68.
Rock-Forming Minerals
Rock-Forming Minerals - most of Earth*s crust is made-up of a small number of minerals.
Uses of Talc
Talc is a soft mineral used in cosmetics, paper, paint, ceramics and many other products.
Triboluminescence
Triboluminescence is flash produced when a mineral is rubbed, scratched or broken.
Geology Tools
Geology Tools - Rock hammers, field bags, hand lenses, maps, hardness picks, gold pans.
Don*t Go To Jail
Mineral collectors must know the rules for removing specimens from public and private property.
Mineral Rights
Mineral Rights - Who owns the minerals under your land? Who wants to buy them?
Geology Dictionary
Geology Dictionary - contains thousands of geological terms with their definitions.
Limonite
Limonite - an amorphous iron oxide. An ore of iron and a pigment since prehistory.
Pyroxene Minerals
Pyroxenes are a group of chain silicate minerals found in igneous and metamorphic rocks.
