Identification Beryl (Aquamarine and Emerald) Identification Sheet The beryllium silicate behind emerald, aquamarine, and morganite: long hexagonal prisms, harder than quartz, in pegmatites.
Identification Azurite Identification Sheet The deep azure-blue copper carbonate, malachite's constant companion, confirmed by its light blue streak and acid reaction.
Identification Corundum (Ruby and Sapphire) Identification Sheet The Mohs 9 anchor at the top of every field kit: ruby and sapphire are the same mineral, identified by extreme hardness and barrel-shaped…
Identification Topaz Identification Sheet The Mohs 8 reference mineral: hard enough to scratch quartz, with perfect basal cleavage and striated prismatic crystals.
Identification Selenite (Gypsum) Identification Sheet A very soft sulfate you can scratch with a fingernail, forming clear bladed crystals, satin spar, and desert roses.
Confectionery Geology Rock Candy (Sucrose Crystal) Identification Sheet A monocrystalline or polycrystalline sucrose formation exhibiting exceptional optical clarity and notable solubility in aqueous environme…
Identification Amethyst Identification Sheet The purple quartz that has captivated collectors and jewelers for millennia — and fades if you leave it on the windowsill.
Identification Feldspar Identification Sheet The mineral that makes up 60% of the Earth's crust — and still trips up new collectors.
Identification Quartz Identification Sheet Field identification cues for quartz and its common varieties, with a decision path for separating it from lookalikes.
