- Chemistry: Fe5(PO4)3(OH)5 - 2H2O,
Hydrated Iron Phosphate Hydroxide.
- Class: Phosphates
- Uses: Only as mineral specimens.
Dufrenite is a classic phosphate mineral.
It is known from classic localities in Devon, England and elsewhere.
Often associated with other rare minerals, dufrenite specimens can easily be a collectors favorite.
Although not particularly colorful unless fresh, dufrenite's muted yellowish-brown color is none-the-less unique and distinctive.
In fact, it produces a nice backdrop to the more colorful minerals that may be attached to the rounded botryoidal landscape.
- Color is yellowish-green or olive when fresh but turns brown when oxidized.
- Luster is varied from vitreous or silky to dull or earthy.
- Transparency: Specimens are translucent to transparent.
- Crystal System is monoclinic; 2/m
- Crystal Habits include botryoidal and globular masses or tabular crystals. Also found in radiating clusters and crusts.
- Cleavage is perfect in two directions.
- Fracture is uneven.
- Hardness is 3.5 - 4.5
- Specific Gravity is approximately 3.1 - 3.3 (slightly above average).
- Streak is yellow-green.
- Associated Minerals include hureaulite, laubmannite, kidwellite, quartz, limonite and rockbridgeite.
- Notable Occurrences include Cornwall, England; Westphalia, Germany; Anglar, France and Cherokee County, Alabama, USA.
- Best Field Indicators are crystal habit, color, associations and streak.