Introduction: Sugilite is a mineral species. Pictured above is sugilite on matrix and a faceted tablet weighing 3.93 ct, displaying the classic grape jelly color.
Colors: semitransparent to opaque, red-purple to blue-purple. It is sometimes sold under the trade names Royal Azel or Royal Lavulite.
Clarity: There is no clarity type classification. Semitransparent material is sometimes faceted and should be eye clean. Cabochons, carvings and beads should be free from cracks.
Stone Sizes: Large pieces have been available.
-Wessels Mine, Kuruman district, near Hotazel, South Africa: Cuttable material was first found in 1975. Around 1980, a huge mass of pehaps 10-12 tons of sugilite was discovered at a depth of 3200 feet. Only half of the material had the grape jelly color associated with the gem and of this, only a tiny percentage (0.1%) was translucent.
-Refractive Index: 1.607-1.610 (+0.001, -0.002). Quartz impurities may alter the RI.
-Birefringence: usually not detectable
-Optic Character: Doubly refractive, uniaxial negative; AGG
-Specific Gravity: 2.74 (+/- 0.05)
-Hardness: 5.5 to 6.5
-Chemical Composition: (K,Na)(Na,Fe)2(Li2Fe)Si12O30
-Cause of Color: Manganese, iron
-Absorption Spectra: 550 nm band, 411, 419, 437 and 445 nm lines
Name: Sugilite is named after Professor Ken-ichi Sugi, the Japanese petrologist who first discovered the material in 1944.
Care: Both the ultrasonic and steam cleaner are risky. Warm, soapy water is safe.
To see available sugilites, click here.