Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Selenite
A clear, soft crystalline variety of gypsum that forms glassy or fibrous wands, so soft it can be scratched with a fingernail.
crystal
Gypsum
A very soft sulfate mineral defining Mohs 2, occurring as selenite, satin spar, alabaster, and desert rose, used to make plaster.
mineral
Rock Gypsum
A soft sedimentary evaporite made of massive gypsum, deposited when sulfate-rich seawater or lake water evaporates and concentrates.
sedimentary
Morganite Crystal
The natural crystal form of morganite, the manganese-colored pink-to-peach variety of beryl popular in romantic jewelry.
crystal
Aquamarine Crystal
The blue iron-bearing variety of beryl, forming clear hexagonal crystals prized both as specimens and as a March birthstone gem.
crystal
Crystal Opal
Precious opal with a transparent or translucent body, letting play-of-color glow with exceptional depth and clarity.
gemstone
Goshenite Crystal
The pure colorless variety of beryl, valued as crystal specimens and as a brilliant alternative to clearer gemstones.
crystal
Emerald Crystal
The natural crystalline form of emerald, the prized green chromium-and-vanadium variety of beryl and the May birthstone.
crystal
Desert Rose
A rosette-shaped cluster of bladed gypsum or barite crystals that traps sand, forming flower-like formations in arid deserts.
mineralGypcrete
A gypsum-rich duricrust that forms by evaporation in arid soils, cementing sediment into a hard surface layer in deserts.
sedimentaryAlabaster
A soft, fine-grained, translucent form of gypsum (or banded calcite) long prized as a carving and ornamental stone.
mineral
Clear Quartz
The pure, colorless form of crystalline quartz, valued for its clarity, abundance, and piezoelectric properties used in electronics.
crystal
Anhydrite
A water-free calcium sulfate mineral closely related to gypsum, forming in evaporite deposits and swelling into gypsum when it absorbs water.
mineral
Rose Quartz
The soft pink, usually cloudy variety of quartz colored by trace titanium or microscopic inclusions, popular for carvings and beads.
crystal
Moonstone
A feldspar gem famous for adularescence, a floating blue-white glow that shimmers across the stone like moonlight.
gemstone
Phantom Quartz
Quartz containing visible internal crystal outlines, formed when growth paused and trapped a layer of mineral inclusions.
crystal
Jelly Opal
A translucent, gelatinous-looking opal whose transparency gives floating, glowing play-of-color a watery, jelly-like appearance.
gemstone
Geode
A hollow rock nodule whose interior cavity is lined with inward-pointing crystals such as quartz, amethyst, or calcite.
mineral
Smoky Quartz
The smoky brown to gray variety of quartz, colored by natural irradiation, valued as both a gemstone and crystal specimen.
crystal
Scepter Quartz
Quartz with a wider crystal 'cap' that grew over a narrower stem, forming a natural scepter or mushroom shape.
crystal
Spirit Quartz
A South African quartz whose central crystal is coated in tiny druzy points, also called cactus or fairy quartz.
crystalLemurian Seed Quartz
Clear quartz crystals marked by distinctive horizontal ladder-like striations, popularized from Brazil as a metaphysical stone.
crystal
Enhydro Quartz
Quartz containing a sealed pocket of ancient water, often with a mobile air bubble that moves when the crystal is tilted.
crystal
Brookite
An orthorhombic titanium dioxide polymorph forming tabular brown to black crystals with brilliant metallic-adamantine luster.
mineral