Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Travertine
A banded, porous limestone deposited by mineral springs, prized as a warm-toned natural building and tile stone.
sedimentary
Ignimbrite
A rock formed from hot pyroclastic flows, often welded, sometimes containing flattened glass lenses called fiamme.
igneous
Red Jasper
An opaque, iron-rich variety of microcrystalline quartz known for its deep brick-red color and ancient history as a stone of strength and grounding.
gemstone
Stibnite
Stibnite is the chief ore of antimony, famous for its dramatic clusters of bladed, silvery-gray metallic crystals.
mineralWhiteschist
A rare high-pressure metamorphic schist defined by the diagnostic assemblage of talc plus kyanite, often pale and silvery.
metamorphic
Larvikite
A Norwegian intrusive rock whose feldspar crystals flash silvery-blue, widely used as blue pearl granite countertops.
igneous
Perthite
An intimate intergrowth of potassium feldspar and sodium feldspar formed when a single alkali feldspar unmixes on cooling, producing fine wavy lamellae.
mineral
Faden Quartz
Tabular quartz crossed by a milky white thread-like line marking where the crystal repeatedly cracked and re-healed.
crystal
Paragonite Schist
A pale, silvery schist dominated by paragonite, the sodium-rich white mica, formed in aluminous metamorphic rocks.
metamorphic
Jaspillite
A banded, metamorphosed iron formation in which bright red jasper alternates with silvery hematite or magnetite layers.
metamorphic