Wesselsite

Formula: SrCuSi₄O₁₀

Origin of name: after locality Wessels mine, Kalahari Manganese field, Kuruman Hill, Cape Province, South Africa

Crystal system: Tetragonal

Crystal class: 4/m 2/m 2/m

Twinning:

Unit cell: a = 7.366, c = 15.574

Colour: Blue

Diaphaneity: Transparent

Luster: Vitreous

Habit: subhedral plates to 5 x 50 x 50 micron, clusters to 200 micron

Hardness:  4-5

Specific gravity: 3.2

Cleavage: 1; {001} perfect

Tenacity: 

Streak: White to light blue white

Synonyms/varieties:

Comments: series with effenbergerite and with cuprorivaite