- Chemistry: Zn2(Fe, Mn)(PO4)2 - 4H2O
, Hydrated Zinc Iron Manganese Phosphate.
- Class: Phosphates
- Uses: As collector's gemstone and as mineral specimens.
Phosphophyllite, whose cumbersome name means "phosphate leaf" in allusion to both its chemistry and cleavage, is a rare zinc and manganese mineral that is found at only a few localities.
It can be most appreciated when cut into gemstones that possess a good blue-green color.
Gemmy phosphophyllite comes from its Bolivian locality where it formed as a primary precipitate in tin rich hydrothermal veins.
In Germany and in New Hampshire, it is found as an alteration product of primary phosphates such as
- Color is blue-green to colorless, gray or black (the latter probably from inclusions).
- Luster is vitreous.
- Transparency crystals are transparent to translucent.
- Crystal System is monoclinic; 2/m.
- Crystal Habits include equant to prismatic individual crystals.
Twinning is common and produces a fishtail contact twin.
- Cleavage is perfect in one direction and distinct in another.
- Fracture is conchoidal.
- Hardness is 3 - 3.5
- Specific Gravity is approximately 3.1 (slightly above average for translucent
- Streak is white.
- Associated Minerals include triphylite,
mica and sulfide ores.
- Notable Occurrences are limited to San Luis Potosi, Bolivia; Palermo Mine, North Groton, New Hampshire, USA and Hagendorf, Germany.
- Best Field Indicators are crystal habit, cleavage, locality and color.