Natural Black 6 Ray Star Sapphire 6.5mm Unheated 1.40ct Round Cabochon

A natural black star sapphire in a classic round cabochon cut, displaying a well-defined 6-ray star that emerges sharply under a single light source. The stone presents a deep dark body with warm brownish-olive undertones, and the golden star sits prominently at the apex of the polished dome — a hallmark of the fine rutile silk that grows within Thai star sapphires.

From Thailand and completely untreated, this round cabochon preserves its natural asterism without any heat treatment or enhancement. The compact 6.5mm size makes it well-suited for rings, pendants, and earrings where the star will be shown off by a bezel or prong setting under direct light.

• Stone type: Natural black star sapphire
• Phenomenon: Asterism (6-ray star)
• Treatment: Untreated
• Cut: Round cabochon
• Size: 6.5mm
• Weight: 1.40ct
• Clarity: Opaque
• Origin: Thailand

Natural black star sapphire, September birthstone - sold loose, single stone.