Sunstone

Hardness: 6-6.5 on Mohs scale; Color: Ranges from colorless, yellow, orange, to red, often with an aventurescence (schiller effect) displaying golden or reddish metallic flashes, which is due to hematite or goethite inclusions; Luster: Vitreous to pearly; Crystal structure: Triclinic; Cleavage: Two distinct cleavages at nearly 90 degrees; Specific Gravity: 2.62-2.67

Sunstone forms in igneous rocks, particularly in certain intermediate to felsic volcanic rocks like basalt or andesite, and occasionally in metamorphic rocks. The aventurescence is caused by tiny, reflective inclusions of hematite or goethite, which align in a specific orientation during the mineral's formation. Geological age varies depending on the host rock, but it is found in formations from various geological periods, including relatively recent volcanic activity.

Primarily used as a gemstone in various forms, including beads (as seen in the image), cabochons, and faceted stones. Its distinctive schiller effect makes it popular for jewelry. It is also collected by mineral enthusiasts.

Oregon Sunstone, a highly prized variety, is naturally colored and comes from basalt flows in Oregon, USA, and can display a wide range of colors and an intense schiller. Historically, sunstone was believed to bring light, happiness, and good fortune.

In the field, sunstone can be identified by its characteristic aventurescence or 'schiller effect' - a spangled glitter caused by light reflecting off minute mineral inclusions. Its color can range from clear to pale yellow, orange, or red. It is commonly found in specific localities around the world, including Oregon (USA), Norway, Russia, India, Canada, and parts of Africa. Collectors look for specimens with strong schiller and desirable color saturation. The beads in the image, with their warm orange tones and potential for subtle glitter, are likely polished sunstone.