THE MINERAL PHOSPHOPHYLLITE

• Chemistry: Zn2(Fe, Mn)(PO4)2 - 4H2O , Hydrated Zinc Iron Manganese Phosphate.
• Class: Phosphates
• Uses: As collector's gemstone and as mineral specimens.
• 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 triphylite.

PHYSICAL CHARACTERISTICS:

• 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 minerals)
• Streak is white.
• Associated Minerals include triphylite, cassiterite, 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.