Rock & Mineral Encyclopedia
Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.
Tourmalinated Quartz
Clear or milky quartz threaded with black needles of tourmaline (schorl), combining quartz clarity with dramatic dark inclusions.
crystal
Talc-carbonate Rock
A soft metamorphic rock made of talc and magnesite or dolomite, formed by hydrothermal alteration of ultramafic rocks.
metamorphic
Yellow Beryl
The yellow variety of beryl, also called heliodor or golden beryl, colored by iron and valued for its bright color and durability.
gemstone
Brown Obsidian
Obsidian colored brown by iron oxide inclusions, frequently banded or swirled with black as in mahogany obsidian.
igneous
Cloudy Obsidian
Obsidian with a hazy, cloud-like translucency caused by uneven distribution of tiny bubbles or incipient crystallites in the glass.
igneous
Monzonite
An intermediate plutonic rock with nearly equal alkali and plagioclase feldspar and very little quartz, sitting between diorite and syenite.
igneous
Apricot Agate
A soft peachy-orange variety of banded chalcedony, naturally iron-tinted or dyed, popular for warm-toned beads and jewelry.
gemstone
Rogue River Jasper
An Oregon picture jasper from the Rogue River area showing earthy scenic patterns in tan, brown, gold, and cream.
mineral
Deschutes Jasper
A prized Oregon picture jasper from the Deschutes region known for soft scenic landscapes in cream, tan, and blue-gray.
mineral
Royal Imperial Jasper
A premium Mexican imperial jasper showing soft pastel swirls and orbicular eyes in lavender, mint, cream, and rust.
mineral
Gary Green Jasper
An Oregon jasper, also called larsonite, of silicified fossil wood showing olive-green fields laced with black dendritic patterns.
mineral
Carrasite Jasper
An orbicular Madagascar jasper related to ocean jasper, showing eyes and swirls in cream, green, and earthy tones.
mineral
Flower Jasper
A jasper whose radiating mineral clusters form flower-like rosettes scattered across an earthy background.
mineral
Banded Iron Formation
Ancient chemically deposited rock of alternating iron-oxide and silica bands recording Earth's early oxygenation and a major iron ore source.
sedimentary
Owyhee Blue Jasper
A soft blue-gray jasper from the Owyhee region of Oregon and Idaho, prized for its rare, calming blue tones among earthy jaspers.
gemstone
Dumortierite
A hard aluminum borosilicate famous for its rich denim-blue color, often forming dense fibrous masses or coloring quartz blue.
mineral
Regency Rose Agate
A prized plume agate with rose-pink and red feathery inclusions suspended in clear chalcedony, from the western U.S.
gemstone
Prase
An old name for a dull leek-green variety of quartz or chalcedony colored by green mineral inclusions, historically called mother of emerald.
crystal
Unakite Jasper
An altered granite of pink feldspar, green epidote and quartz, mottled pink-and-green and popular as a tumbled and carving stone.
metamorphic
Black Agate
A deep black variety of banded chalcedony, often closely related to or treated like onyx, used for jewelry and carvings.
gemstone
Graveyard Point Agate
A celebrated plume agate from the Oregon-Idaho border, known for dramatic black, gold, and red plumes in clear chalcedony.
gemstone
Carnelian
A warm orange-to-red variety of chalcedony quartz colored by iron oxide, used since antiquity for seals, beads, and cabochons.
gemstone
Holley Blue Agate
A rare translucent lavender-blue agate from the Holley area of Oregon, prized for its soft purple-blue color.
gemstone
Tourmaline Schist
A foliated schist threaded with black tourmaline (schorl) needles, marking boron-rich metamorphic or metasomatic conditions.
metamorphic