Rock & Mineral Encyclopedia

Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.

Larimar

A rare sky-blue variety of pectolite found only in the Dominican Republic, prized for its sea-like color and white volcanic patterning.

A green, glauconite-rich marine sandstone that records slow deposition on continental shelves and is used as a soil amendment.

A bright emerald-green glass sold as obsidian; saturated transparent green is manufactured, while rare natural green obsidian is only faintly tinted.

A single beryl crystal showing two distinct color zones, such as aquamarine blue grading into morganite pink, within one stone.

A limestone packed with visible shells and shell fragments, recording the accumulation of marine invertebrate remains on ancient sea floors.

A brecciated, chatoyant quartz with swirling blue, gold, and brown fibers that shimmer like a stormy sky.

A translucent apple-green chalcedony colored by nickel, the most prized green variety of the quartz family.

A microcrystalline quartz jasper marked by small concentric ring or eye patterns that resemble the eyes of birds.

A banded variety of chalcedony quartz, famed for its colorful concentric layers and enormous range of patterns and colors.

Rutile is a major titanium ore and the famous golden needle inclusion that gives rutilated quartz its shimmering threads.