Sugilite

Sugilite is a rare manganese-rich potassium-sodium-lithium cyclosilicate famous for its intense royal-purple to magenta gem-grade material from the Wessels mine, South Africa. It became a major Asian gem market favorite from the 1990s onward.

Properties

• Formula: KNa₂(Fe,Mn,Al)₂Li₃Si₁₂O₃₀
• Crystal system: Hexagonal
• Hardness: 5.5 – 6.5
• Color: Royal purple, magenta, violet, pink (gem grade); also brownish-yellow
• Streak: White
• Luster: Vitreous to dull (massive)
• Cleavage: Poor
• Density: 2.7 – 2.8 g/cm³

Occurrence

Discovered in 1944 at Iwagi Islet (Japan, type locality, named for petrologist Ken-ichi Sugi) but only known as drab brownish material. The world’s gem-grade purple sugilite comes from a single source: the Wessels Mn mine, Kalahari, South Africa, in massive nodular form within manganese ores.

Identification

Intense royal-purple color (gem variety) + association with manganese ore + South African pedigree. Distinguish from charoite (purple but fibrous-felted texture), purple jadeite (different chemistry), and dyed materials by SG and IR.

Collector Notes

Wessels gel-sugilite (the highest grade) is a premier Asian collector gem, particularly in Japan and Taiwan markets. Massive nodules cut into cabochons and beads. Rare sharp crystals essentially do not exist.