Ungarettiite

Formula: NaNa₂(Mn₂Mn₃)Si₈O₂₂O₂

Origin of name: Named after Prof. Luciano Ungaretti (1942-), Universita de Pavia, Pavia, Italy.

Crystal system: monoclinic

Crystal class: 2/m

Twinning:

Unit cell: a = 9.89, b = 18.04, c = 5.29, β = 104.6°

Colour: Cherry-red to dark red

Diaphaneity: Transparent

Luster: Vitreous - adamantine

Habit: Prismatic grains to 1 mm long, granular

Hardness: 6

Specific gravity: 3.52

Cleavage: 1; {110} perfect

Tenacity: Brittle

Streak: Pale pinkish white

Synonyms/varieties:

Comments: member of the amphibole group