Identification Olivine (Peridot) Identification Sheet The green mineral that makes up much of the Earth's mantle — and surfaces as gemstone peridot when conditions align.
Identification Turquoise Identification Sheet One of the world's oldest ornamental stones — and one of the most frequently faked.
Identification Obsidian Identification Sheet Volcanic glass that looks like a mineral but technically isn't — and produces the sharpest natural edges known.
Identification Fluorite Identification Sheet The mineral that gave fluorescence its name — and comes in nearly every color imaginable.
Identification Pyrite (Fool's Gold) Identification Sheet How to tell pyrite from actual gold — and why every newcomer gets fooled at least once.
Identification Calcite Identification Sheet How to confirm calcite using hardness, cleavage, and the dilute-acid reaction test.
