Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Paintbrush Jasper
A scenic jasper whose flowing streaks of warm color resemble strokes left by a loaded paintbrush.
mineral
Boulder Opal
Precious opal that forms in thin veins within brown ironstone boulders, cut with the host rock left as a natural dark backing.
gemstone
Lithium Quartz
A quartz crystal containing pink to lilac lithium-bearing mineral inclusions that give a soft cloudy lavender or rose coloration.
crystal
Hyalophane
A barium-bearing potassium feldspar intermediate between orthoclase and celsian, found in barium-rich metamorphic and ore deposits.
mineral
Bumblebee Jasper
A vivid yellow-and-black banded stone from Indonesian volcanic vents, colored by sulfur, arsenic minerals and iron oxides, not true jasper.
sedimentary
Graphic Feldspar
A pegmatite rock of feldspar intergrown with wedge-shaped quartz that resembles ancient runic or Hebrew writing.
igneous
Blue Quartz
A naturally blue quartz colored by tiny mineral inclusions such as dumortierite or scattered rutile and tourmaline fibers.
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
Garden Quartz
Clear quartz filled with mineral inclusions that look like underwater gardens, mossy landscapes, or floating scenery.
crystalOutback Jasper
An earthy Australian-style jasper in red, ochre, and yellow tones evoking the colors of the Outback desert.
mineral
Spessartite Garnet
A manganese aluminum garnet glowing in vivid orange to reddish-orange tones, with the finest called mandarin garnet.
gemstone
Claystone
A very fine-grained sedimentary rock made mostly of clay minerals, smooth to the touch and lacking the gritty feel of siltstone.
sedimentary
Green Marble
A green ornamental stone, often serpentine-rich marble or verde antique, valued for its rich green color and white veining.
metamorphic
Grape Agate
Clusters of tiny botryoidal chalcedony spheres resembling bunches of grapes, famously purple, found in Indonesia.
mineralTripolite
A soft, lightweight siliceous sedimentary rock made of fossil diatom remains, prized as a fine natural abrasive and polishing powder.
sedimentaryArizona Ruby
Arizona Ruby is a chromium-rich pyrope garnet from Arizona, often gathered from anthills, valued for its intense ruby-like red.
gemstone
Pyrope Garnet
The magnesium-rich garnet famed for its intense blood-red 'fire,' historically the Bohemian garnet of Victorian jewelry.
gemstoneRegency Rose Agate
A prized plume agate with rose-pink and red feathery inclusions suspended in clear chalcedony, from the western U.S.
gemstone
Goldstone
A man-made glittering glass packed with tiny copper crystals, traditionally reddish-brown but also made in blue and green.
crystalGraveyard Point Agate
A celebrated plume agate from the Oregon-Idaho border, known for dramatic black, gold, and red plumes in clear chalcedony.
gemstone
Crazy Lace Agate
A Mexican banded agate famous for tightly swirling, contorted lacy patterns in warm reds, creams, and golds.
mineral
Blue Jasper
An opaque blue variety of chalcedony jasper, less common than red or green forms, colored by mineral inclusions.
mineral
Tourmaline
A boron-rich silicate gemstone group famous for occurring in every color of the rainbow, sometimes several within a single crystal.
gemstone
Elbaite
The lithium-rich tourmaline species responsible for nearly all gem tourmaline, occurring in every color of the rainbow.
mineral