Black star diopside 2.92ct 9x7mm oval cabochon

An oval black diopside cabochon with a four-ray star whose arms appear slightly wider and more diffuse than on some others in the group, giving the cross a soft, brushed quality rather than sharp lines. The star is clearly visible and the intersection of the arms sits near the stone's center. Some natural surface grain is visible at close range. Deep, opaque black body color with a good gloss polish.

Asterism describes the star of light that appears across the surface of a cabochon when a gem contains fine needle inclusions oriented in crossing directions, each set reflecting light into a single perpendicular ray. In black star diopside, two sets of rutile needles lying at 90 degrees to one another within the crystal produce this four-armed cross. The breadth of the arms reflects the natural distribution of those inclusions in this particular stone, and no treatment has been applied.

• Stone type: Natural diopside
• Weight: 2.92 ct
• Size: 9x7.2 mm
• Color: Black
• Phenomenon: Asterism (4-ray star)
• Cut: Oval cabochon
• Clarity: Opaque
• Treatment: Untreated
• Origin: Africa
• Hardness: 5.5-6 (Mohs)

Natural black star diopside, untreated, asterism, sold loose.