Sugilite ( ) is a relatively rare pink to purple

cyclosilicate Silicate minerals are rock-forming minerals made up of silicate groups. They are the largest and most important class of minerals and make up approximately 90 percent of Earth's crust. In mineralogy, the crystalline forms of silica (silicon dio ...

mineral with the complex chemical formula K Na₂( Fe, Mn, Al)₂ Li₃ Si₁₂ O₃₀. Sugilite crystallizes in the

hexagonal In geometry, a hexagon (from Greek , , meaning "six", and , , meaning "corner, angle") is a six-sided polygon. The total of the internal angles of any simple (non-self-intersecting) hexagon is 720°. Regular hexagon A regular hexagon is d ...

system with prismatic crystals. The crystals are rarely found and the form is usually massive. It has a

Mohs hardness The Mohs scale ( ) of mineral hardness is a qualitative ordinal scale, from 1 to 10, characterizing scratch resistance of mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fair ...

of 5.5–6.5 and a

specific gravity Relative density, also called specific gravity, is a dimensionless quantity defined as the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity for solids and liquids is nea ...

of 2.75–2.80. It is mostly translucent. Sugilite was first described in 1944 by the Japanese

petrologist Petrology () is the branch of geology that studies rocks, their mineralogy, composition, texture, structure and the conditions under which they form. Petrology has three subdivisions: igneous, metamorphic, and sedimentary petrology. Igneous an ...

Ken-ichi Sugi (1901–1948) for an occurrence on Iwagi Islet,

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

, where it is found in an aegirine syenite intrusive

stock Stocks (also capital stock, or sometimes interchangeably, shares) consist of all the Share (finance), shares by which ownership of a corporation or company is divided. A single share of the stock means fractional ownership of the corporatio ...

. It is found in a similar environment at Mont Saint-Hilaire,

Quebec Quebec is Canada's List of Canadian provinces and territories by area, largest province by area. Located in Central Canada, the province shares borders with the provinces of Ontario to the west, Newfoundland and Labrador to the northeast, ...

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. In the Wessels mine in Northern Cape Province of

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

, sugilite is mined from a strata-bound

manganese Manganese is a chemical element; it has Symbol (chemistry), symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese was first isolated in the 1770s. It is a transition m ...

deposit. It is also reported from

Liguria Liguria (; ; , ) is a Regions of Italy, region of north-western Italy; its Capital city, capital is Genoa. Its territory is crossed by the Alps and the Apennine Mountains, Apennines Mountain chain, mountain range and is roughly coextensive with ...

and

Tuscany Tuscany ( ; ) is a Regions of Italy, region in central Italy with an area of about and a population of 3,660,834 inhabitants as of 2025. The capital city is Florence. Tuscany is known for its landscapes, history, artistic legacy, and its in ...

Italy Italy, officially the Italian Republic, is a country in Southern Europe, Southern and Western Europe, Western Europe. It consists of Italian Peninsula, a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land b ...

;

New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

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and

Madhya Pradesh Madhya Pradesh (; ; ) is a state in central India. Its capital is Bhopal and the largest city is Indore, Indore. Other major cities includes Gwalior, Jabalpur, and Sagar, Madhya Pradesh, Sagar. Madhya Pradesh is the List of states and union te ...

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. Sugilite is commonly pronounced with a soft "g", as in "ginger". However, as with most minerals, its pronunciation is intended to be the same as the person it is named after; in this case, the Japanese name Sugi has a hard "g", as in "geese". The mineral is also referred to as lavulite, luvulite, and royal azel by gem and mineral collectors. In Japan, sugilite is found as yellowish-white to colourless, and is not good for jewellery. Sugilite-162617

References

{{Manganese minerals Potassium minerals Sodium minerals Iron minerals Manganese minerals Aluminium minerals Lithium minerals Cyclosilicates Gemstones Hexagonal minerals Minerals in space group 192 Minerals described in 1944

See also

References