Rock Identifier

Rock & Mineral Encyclopedia

Search and identify 1,000+ rocks, minerals, crystals, and gemstones — with properties, formation, colors, hardness, and how to tell them apart.

Citrine

Citrine

The golden-yellow variety of quartz, ranging from pale lemon to deep madeira amber, often produced by heating amethyst.

gemstone
Yellow Beryl

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
Yellow Opal

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

Yellow Jasper

An opaque yellow-to-golden variety of jasper, an iron-stained microcrystalline quartz prized for warm color and durable polish.

gemstone
Lemon Quartz

Lemon Quartz

A vivid greenish-yellow quartz, usually heat-treated or irradiated, prized for its clean clarity and bright lemon color.

crystal
Golden Healer Quartz

Golden Healer Quartz

Quartz colored or coated by golden iron oxides such as limonite or goethite, giving a warm sunlit yellow glow.

crystal
Ametrine

Ametrine

A natural bicolor quartz that combines purple amethyst and golden citrine in a single crystal.

crystal
Prasiolite

Prasiolite

A pale green variety of quartz, usually created by heat-treating amethyst, often marketed as green amethyst.

gemstone
Mustard Jasper

Mustard Jasper

A warm mustard-to-ochre yellow jasper colored by iron, valued by lapidaries for its rich, earthy golden tone.

gemstone
Butterstone Jasper

Butterstone Jasper

A soft-toned cream-to-butterscotch jasper colored by iron oxides, prized by lapidaries for its smooth, even, opaque finish.

gemstone
Honey Agate

Honey Agate

A warm golden to amber translucent chalcedony agate whose color and glow resemble honey, sometimes with banding.

gemstone
Loess

Loess

A loose, wind-blown silt deposit, typically buff-colored and very fertile, that forms thick blankets and stands in steep cliffs.

sedimentary
Yellow Agate

Yellow Agate

A yellow to golden banded chalcedony colored by iron, ranging from natural honey tones to dyed commercial stones.

gemstone
Yellow Garnet

Yellow Garnet

A trade term for yellow garnets, including golden grossular, yellow andradite (topazolite), and yellow-green Mali garnet.

gemstone
Yellow Obsidian

Yellow Obsidian

Yellow to golden volcanic glass; natural examples owe their color to iron, though much bright yellow obsidian on the market is manufactured glass.

igneous
Yellow Tourmaline

Yellow Tourmaline

Bright yellow to golden tourmaline colored by manganese, with the most vivid canary stones among the rarest tourmaline hues.

gemstone
Quartzite

Quartzite

An extremely hard metamorphic rock formed from sandstone, made of fused quartz grains that break across rather than between the grains.

metamorphic
Yellow Labradorite

Yellow Labradorite

A transparent yellow to golden gem variety of labradorite feldspar, usually faceted to show its clear, warm color.

gemstone
Rose Quartz

Rose Quartz

The soft pink, usually cloudy variety of quartz colored by trace titanium or microscopic inclusions, popular for carvings and beads.

crystal
Snow Quartz

Snow Quartz

An opaque, snow-white variety of quartz whose milky color comes from countless tiny gas and fluid inclusions.

crystal
Yellow-Green Obsidian

Yellow-Green Obsidian

A chartreuse yellow-green glass sold as obsidian; the bright color is manufactured and does not occur in natural volcanic glass.

igneous
Smoky Quartz

Smoky Quartz

The smoky brown to gray variety of quartz, colored by natural irradiation, valued as both a gemstone and crystal specimen.

crystal
Milky Quartz

Milky Quartz

The most common variety of quartz, milky white from microscopic fluid and gas inclusions, forming massive veins worldwide.

crystal
Blue Quartz

Blue Quartz

A naturally blue quartz colored by tiny mineral inclusions such as dumortierite or scattered rutile and tourmaline fibers.

crystal