SUNSTONE

Sunstone and Aventurine, a kind of quartz that displays the same glistening Aventurescence appearance, are quite similar in habits. Sunstone is occasionally dubbed 'Aventurine Feldspar' to distinguish it from its Quartz cousin. Aventurine occasionally occurs as orange or red, but it is typically green, whereas Sunstone is always an orange or reddish color.

Sunstone often has a red, orange, or golden yellow glitter look. There is a very small chance that it will be green or blue. Star Sunstone refers to stones that occasionally exhibit an asterism in the shape of a four-rayed star in sunstone. Moreover, sunstone occasionally exhibits a cat's eye phenomenon.

The optical appearance is caused by reflections from tiny scale-like inclusions of red copper, hematite, or goethite that are parallel to the main cleavage plane and have irregular, hexagonal, or rhombic shapes. Sunstone is also referred to as "aventurine-feldspar" because of the inclusions that give the stone an appearance resembling that of aventurine. Copper is responsible for Oregon Sunstone's hue and for the optical phenomenon known as schiller. This crystal's center sparkles, and typically, the hue is darker in the center and lighter toward the edges.

Although the effect can occasionally be seen in orthoclase, oligoclase is the feldspar that typically exhibits the aventurine look, leading to the distinction between two types of sunstone called "oligoclase sunstone" and "orthoclase sunstone."

• Oregon Sunstone is sunstone that comes from one of the state's several sunstone mines.
• A sunstone with the appearance of a four-rayed star due to an asterism is known as a star sunstone.