Mineral

Sunstone

Plagioclase Feldspar (specifically Oligoclase variety with hematite or goethite inclusions) Chemical Formula: (Ca,Na)(Al,Si)2Si2O8

Hardness: 6-6.5 on Mohs scale. Color: Ranges from colorless, yellow, orange, pink to reddish-brown, often with a shimmering or spangled effect (aventurescence). Luster: Vitreous to pearly. Crystal Structure: Triclinic. Cleavage: Good in two directions at nearly right angles. Specific Gravity: 2.62-2.67.

Hardness: 6-6
Luster: Vitreous to pearly

Identified November 1, 2025More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Sunstone is typically found in igneous rocks such as basalt, andesites, and rhyolites, as well as in some metamorphic rocks and placer deposits. Its aventurescence is caused by minute hematite or goethite inclusions that reflect light, producing a glittering effect.

Uses & applications

Predominantly used as a gemstone in jewelry, particularly for cabochons, beads (as seen in the image), and carvings. High-quality sunstone with strong aventurescence is highly prized.

Geological facts

Sunstone is the state gemstone of Oregon, USA, where it occurs in relatively large and clear crystals with strong aventurescence. The "schiller" or sparkle in sunstone is due to oriented microscopic platelets of hematite or goethite, giving it a unique optical phenomenon often called "aventurescence."

Field identification & locations

In the field, look for feldspar crystals with a distinct orange, red, or golden hue and a shimmering play of light when rotated. It is commonly found in India, Canada, Norway, Russia, Tanzania, the USA (Oregon), and Mexico. Collectors look for specimens with intense color and strong, even aventurescence. Distinguishing it from other aventurescent minerals like aventurine quartz requires testing hardness and cleavage.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Epidote

Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

metamorphic

Nephrite Jade

Nephrite

Mineral/Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Metamorphic Rock

Green Apatite on Albite

Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]

mineral

Epidote

Epidote - Ca2(Al2,Fe3+)3(SiO4)3(OH)

mineral