Lomonosovite

Formula:  Na₂Ti₂Si₂O₉ ^. Na₃PO₄

Origin of name:  For M. Lomonosov, Russian mineralogist

Crystal system:  Triclinic

Crystal class:  -1

Twinning: 

Unit cell: 

Colour:  Dark cinnamon brown to black, rose-violet, pinkish violet

Diaphaneity:  Transparent in thin fragments

Luster:  Vitreous to adamantine on cleavage

Habit:  Crystals tabular, laminated

Hardness:  3 to 4

Specific gravity:  3.15

Cleavage:  1; {100} perfect

Tenacity: 

Streak:  Light rose-cinnamon

Synonyms/varieties:

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