- Chemistry: Li(Fe, Mn)PO4, Lithium Iron Manganese Phosphate.
- Class: Phosphates
- Uses: As a source of lithium and phosphorus and as mineral
Triphylite is a rather scarce phosphate mineral.
It forms a solid solution series with the often associated mineral
Lithiophilite's formula is Li(Mn, Fe)PO4 and differs from triphylite by
being rich in manganese instead of iron. The structures of the two minerals are the same and
therefore any differences in physical properties between the two would be related to the
iron/manganese percentage. Lithiophilite is slightly less dense and is pinkish to greenish brown
whereas triphylite's color tends toward blue and blue gray. The series is often called the
"triphylite series" and the two minerals are often listed together in mineral field guides and
reference manuals. Triphylite's name in Greek means "family of three" and is probably
referring to the three ions: lithium, iron and manganese.
Although triphylite generally does not form good crystals, it does have a wonderful although
indirect benefit to the mineral world. Triphylite is a primary phosphate mineral found in
phosphatic pegmatites and pegmatitic dikes. It alters easily into other phosphate minerals,
especially manganese phosphates. These rare phosphate minerals are usually brightly colored and
make wonderful mineral specimens. Some mines have been made famous by their suites of unusual
and beautiful secondary phosphate minerals such as
to name a few.
And where did these phosphates come from?
They are the products of the alteration and/or weathering of triphylite,
and a few other primary phosphate minerals.
A lot of respect should be shown to triphylite and the other primary phosphate minerals for
making these other minerals possible.
- Color is blue, gray-blue and gray-blue-green.
- Luster is vitreous.
- Transparency: Specimens are transparent to translucent.
- Crystal System is orthorhombic; 2/m 2/m 2/m
- Crystal Habits do not include well formed crystals because most crystals are embedded
and appear as compact, cleavage masses and intergrown crystal clumps.
- Cleavage is near perfect in one direction (basal) and imperfect in two directions
(prismatic). All cleavages are at right angles to each other.
- Fracture is uneven.
- Hardness is variable from 4 - 5
- Specific Gravity is approximately 3.58 (above average), but decreases with decreased
- Streak is white to grayish-white.
- Other Characteristics: When powdered and placed in a gas flame, it gives the flame a
bright red color and this indicates the presence of lithium. Hyper-weathering produces a black
stain of manganese oxides.
- Associated Minerals include lepidolite,
and various manganese oxides.
Associated secondary phosphates include
- Notable Occurrences are widespread and include Verutrask, Sweden; Mangualde,
Portugal; Bavaria, Germany; Buckfield, Poland; Karidid District, Namibia; Namaqualand, South
Africa; the Buranga pegmatite, Rwanda; Yellowknife, Northwest Territories, Canada; Rajasthan,
India; Rio Grande do Norte, Brazil and Pilbara District, Australia. In the United States
localities include Pala District of San Diego County, California; Newry, Stoneham and Topsham,
Maine; Palermo Quarry, North Groton, New Hampshire; Custer, South Dakota and Branchville,
Fairfield County, Connecticut.
- Best Field Indicators are color, associations, environment, cleavage and density.