Minehillite

Formula:  (K,Na)_2-3Ca₂₈Zn₄Al₄Si₄₀O₁₁₂(OH)₁₆

Origin of name:  From locality; Mine Hill, Franklin NJ

Crystal system:  Hexagonal

Crystal class:  -3 2/m

Twinning: 

Unit cell: 

Colour:  Colourless, white to grayish black

Diaphaneity: 

Luster:  Vitreous

Habit:  Plates to 5 mm, in aggregates

Hardness:  4

Specific gravity:  2.93

Cleavage:  1; {0001} perfect

Tenacity: 

Streak: 

Synonyms/varieties:

Comments: