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Mixed Minerals

Saturday, 13 January 2018 12:00 PM

Introducing the "Mixed Minerals" gallery which is part of our New Additions galleries. This gallery contains mineral specimens for sale including pharmacosiderite, and strengite and more from places like Wheal Gorland, St. Day dist., Cornwall, England, and Three Oaks Gap, Polk Co., Arkansas, United States.

Pharmacosiderite

with Scorodite - #BN48217
Locality
Wheal Gorland, St. Day dist., Cornwall, England 
Formula
KFe3+4(AsO4)3(OH)4·6-7H2
Availability
Available
Price
$75.00
Size
6 x 4.5 x 2.5 cm - Sm Cabinet 
Tagged
arsenate  

Grass green to bright green Pharmacosiderite crystals to about 0.75mm with grey to bluish Scorodite. The Scorodite is not as blue as the digital photos depict it as. A hand-written label says it was collected about 1977-1979.


Pharmacosiderite

Formula
KFe3+4(AsO4)3(OH)4·6-7H2
Crystal System
Isometric 
Crystal Habit
Blocky, Crystalline - Coarse, Earthy 
Cleavage
Indistinct, None, None 
Luster
Adamantine - Resinous 
Color
olive green, emerald green, reddish brown, yellowish brown, honey yellow 
Streak
yellowish green 
Class
Isometric - Hextetrahedral 
Fracture
Brittle - Sectile 
Hardness
2.5 
Collection
Dr. Buford Nichols Collection

Strengite

on Kidwellite with Cacoxenite & Beraunite - #BN48220
Locality
Three Oaks Gap, Polk Co., Arkansas, United States 
Formula
Fe3+PO4·2H2
Availability
Available
Price
$195.00
Size
5.5 x 4.5 x 3 cm - Sm Cabinet 
Tagged
phosphate  

Light purple crystal clusters of Strengite to 2mm on light to dark green Kidwellite. Look closely along the edges and golden yellow fibrous crystals of fytikish habit Cacoxenite can be seen. Outward closer to the matrix are dark bands of gorgeous, concentric Beraunite. It is a fine specimen, not to be found in today's world. Don't bother looking up fytikish, I made it up.


Strengite

Formula
Fe3+PO4·2H2
Crystal System
Orthorhombic 
Crystal Habit
Spherical, Radial, Botryoidal 
Cleavage
Good, Poor, None 
Luster
Vitreous (Glassy) 
Color
colorless, pale violet, deep violet, red, carmine red 
Streak
white 
Class
Orthorhombic - Dipyramidal 
Fracture
Brittle - Conchoidal 
Hardness
3.5 
Collection
Dr. Buford Nichols Collection
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