Sugilite

Sugilite properties at a glance

Geology & background

Sugilite is a rare cyclosilicate that forms in manganese-rich metamorphic rocks and alkaline igneous rocks, with gem-grade purple material occurring in manganese ore bodies.

Described in 1944 from Japan, sugilite remained obscure until the discovery of rich purple material in South Africa in the 1970s and 1980s made it a popular lapidary and ornamental stone.

How to identify Sugilite

• Look for solid, massive purple to magenta material rather than distinct crystals.
• Moderate hardness near 6, lack of cleavage, and association with manganese minerals are strong clues.
• Color can range from pale lilac to deep royal purple, so confirm rare or costly stones with proper testing.

Where Sugilite is found

Sugilite occurs in manganese-rich and alkaline metamorphic rocks, with the main gem source in South Africa and other occurrences in Japan, Italy, Canada, India, and Australia.

How much is Sugilite worth?

Value depends on color intensity, evenness, translucency, freedom from matrix, and material quality.

Common uses

• Cabochons and ornamental stone
• Beads and carvings
• Collector specimens
• Jewelry

Interesting facts

• Sugilite was named for the Japanese petrologist Ken-ichi Sugi, who first found it.
• Gem-quality purple sugilite comes almost entirely from manganese mines in South Africa.
• It is sometimes called the purple turquoise because of its use as an opaque ornamental stone.
• Most sugilite is massive, so well-formed crystals are extremely rare and prized.

Care & safety

Sugilite is fairly hard and tough with no cleavage, making it reasonably durable for jewelry.

Avoid inhaling dust. Do not cut, grind, or polish unknown specimens without eye protection and a proper respirator.

Related rocks & minerals

Aegirine Minerals Quartz Quartz Family Jadeite Silicate Minerals Kaolinite Silicate Minerals Lazurite Silicate Minerals Leucite Silicate Minerals