The sunstone is a plagioclase feldspar which, when viewed from certain angles, exhibits a striped appearance. It has been found in southern Norway, Sweden, various locations in the United States and on some beaches along the central coast of southern Australia. The optical effect appears to be due to the reflections of the red copper inclusions, in the form of minute scales, which are hexagonal, rhombic or irregular in shape, and are arranged parallel to the main cleavage plane. These inclusions give the stone an Aventurine-like appearance, so the Sun Stone is also known as "Aventurine-Feldspar". The central part of this crystal shines and usually the color is darker in the center and becomes lighter towards the outer edges.
Dimensions
Height (cm): 1
Depth (cm): 0.2
Width (cm): 1
Weight (g): 1
Property
Chemical Formula: (Ca, Na) ((Al, Si) 2Si2O8)
Mohs scale: 6 - 6.5
Relative density: 2.64-2.66
Crystalline System: Triclino