Zaccagnaite

Formula: Zn₄Al₂(CO₃)(OH)₁₂.3H₂O

Origin of name: For Domenico Zaccagna (1851-1940), a scholar and mineral collector who specilized in the geology and mineralogy of the Carrara marbles of the of the Apuan Alps of northern Tuscany, Italy - where the species was discovered.

Crystal system: Hexagonal

Crystal class: 6/m 2/m 2/m

Twinning: 

Unit cell: a = 3.0725 Å, c = 15.1135 Å

Colour: White

Diaphaneity: Transparant

Luster: Vitreous

Habit: Microscopic Crystals - Crystals visible only with microscopes., Hexagonal - Six-sided crystal shape in cross-section or habit., Prismatic - Crystals Shaped like Slender Prisms

Hardness: 

Specific gravity: 2.82 (calculated)

Cleavage: 

Tenacity: 

Streak: White

Synonyms/varieties:

Comments:  Member of the hydrotalcite group