THE MINERAL DUFRENITE

  • Chemistry: Fe5(PO4)3(OH)5 - 2H2O, Hydrated Iron Phosphate Hydroxide.
  • Class: Phosphates
  • Uses: Only as mineral specimens.
  • 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.

PHYSICAL CHARACTERISTICS:

  • 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.
DUFRENITE specimens:
(hover for more info)
DUFRENITE specimen duf-1
$ 42.00
Dims: 1.3 x 1.0 x 0.7" (3.4 x 2.5 x 1.7 cm)
Wt: 16 g
Iron Knob, South Australia, Australia
This thumbnail piece consists mostly of botryoidal Dufrenite. The material has either a deep brown or a pale rusty-brown coloration depending on its level of oxidation, and its luster likewise ranges from silky to dull and earthy according to oxidation. Though no triclinic crystals are evident, it does show its classic botryoidal formation and some integral layering. There does not appear to be any base or host material present.
no photo
duf-1 ($ 42.00)
Iron Knob, South Australia, Australia
DUFRENITE specimen duf-2
$ 28.00
Dims: 1.0x0.9x0.7" (2.5x2.4x1.8cm)
Wt: 0.55 oz. (15.7g)
Penikla, Czech Republic
This specimen contains a thin layer of radiating dufrenite crystals on a host rock. The dufrenite has oxidized to a rich brown color, with an earthy luster. The host rock contains several different minerals, including more dufrenite and some goethite.
no photo
duf-2 ($ 28.00)
Penikla, Czech Republic
DUFRENITE specimen duf-3
$ 28.00
Dims: 1.0x0.9x0.7" (2.5x2.4x1.8mm)
Wt: 0.20 oz. (5.7g)
Penikla, Czeckoslovakia
This is a chunk of massive dufrenite, showing no crystal form. One surface is lighter in color, showing the proper brown color of freshly oxidized dufrenite. The remaining surfaces are much darker in color, likely due to coatings of other minerals.
no photo
duf-3 ($ 28.00)
Penikla, Czeckoslovakia

 


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