Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Yellow Agate
A yellow to golden banded chalcedony colored by iron, ranging from natural honey tones to dyed commercial stones.
gemstone
Yellow Opal
A cheerful yellow opal ranging from translucent common opal to golden fire opal, colored by trace iron in the silica.
gemstone
Yellow Jasper
An opaque yellow-to-golden variety of jasper, an iron-stained microcrystalline quartz prized for warm color and durable polish.
gemstone
Lemon Opal
A bright lemon-yellow opal, usually common opal, valued for its cheerful citrus color and translucent glow.
gemstone
Gold Opal
A golden-toned opal ranging from translucent common opal to precious stones flashing color against a warm yellow body.
gemstoneHoney Opal
A warm golden-to-amber opal ranging from translucent common opal to precious stones that flash play-of-color over a honey body.
gemstone
Moss Opal
A common opal containing moss- or fern-like mineral inclusions that resemble plants suspended in a pale silica body.
gemstone
Honey Agate
A warm golden to amber translucent chalcedony agate whose color and glow resemble honey, sometimes with banding.
gemstone
Blue Opal
A soft blue common opal, famously from Peru, valued for its serene sky-to-teal color rather than play-of-color.
gemstone
Indian Agate
An affordable multicolored banded and mossy chalcedony from India, common in tumbled stones, beads, and meditation pieces.
gemstone
Fire Opal
A translucent to transparent opal in warm yellow, orange, and red tones, prized for body color rather than play-of-color.
gemstone
Flame Agate
A chalcedony agate with red, orange, and yellow plume or banding patterns that rise like dancing flames within the stone.
gemstoneCat's Eye Opal
An opal cut to show chatoyancy, a sharp moving band of light like a cat's eye, usually in honey, green or yellow common opal.
gemstoneOwyhee Blue Agate
A soft sky-blue chalcedony from the Owyhee region of Oregon and Idaho, prized for its calming, opaque powder-blue color.
gemstoneButterstone Jasper
A soft-toned cream-to-butterscotch jasper colored by iron oxides, prized by lapidaries for its smooth, even, opaque finish.
gemstone
Orthoclase
A common rock-forming potassium feldspar, the Mohs hardness reference at 6, found in granites and used in ceramics and glassmaking.
mineralFlame Jasper
A fiery jasper whose red, orange, and yellow plumes lick across the stone like flames against an earthy background.
mineral
Ocean Jasper
A multicolored orbicular chalcedony from Madagascar famous for its circular eye-like orbs in greens, pinks, whites, and yellows.
sedimentary
Mookaite
A vivid Australian jasper-like silica stone in earthy reds, yellows, and purples, formed from silicified radiolarian sediment.
mineral
Montana Moss Agate
A translucent chalcedony from Montana filled with black and red dendritic inclusions that look like moss, ferns, or scenic landscapes.
gemstone
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
Septarian Concretion
A rounded sedimentary nodule cracked internally and filled with veins of yellow calcite, prized for its striking dragon-skin patterning.
sedimentaryNoreena Jasper
A rare Australian jasper from the Pilbara with bold red, yellow, and black abstract patterns, prized by collectors.
mineral
Palagonite
A yellow-brown alteration material formed when basaltic volcanic glass reacts with water, common in hydrovolcanic tuffs and pillow lavas.
igneous