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Southeast US Phosphates

Thursday, 23 April 2020 08:00 PM

Introducing the "Southeast US Phosphates" gallery which is part of our Special Edition galleries. This gallery contains mineral specimens for sale including kidwellite, phosphosiderite, and straczekite and more from places like York mine, Polk Co., Arkansas, United States, Three Oaks Gap, Polk Co., Arkansas, United States, Williams prospect, Coosa Co., Alabama, United States, and Union Carbide mine, Wilson Springs, Garland Co., Arkansas, United States.

Kidwellite

with Beraunite - #BN53053
Locality
York mine, Polk Co., Arkansas, United States 
Formula
NaFe3+9(PO4)6(OH)11·3H2
Availability
Sold
Size
4.5 x 2.5 x 2.5 cm - Miniature 
Tagged
phosphate  

This is a little gem of a specimen showing the cross-sections of Kidwellite spheres. The sections are 1mm across and are concentrically zoned in color and probably composition. You would need to scan these with an EDS to determine the chemical phases and would probably turn up Dufrenite and Rockbridgeite. The Beraunite is on the sides of the specimen as embedded dark red blades.


Kidwellite

Formula
NaFe3+9(PO4)6(OH)11·3H2
Crystal System
Monoclinic 
Crystal Habit
Fibrous, Columnar 
Cleavage
Perfect, None, None 
Luster
Silky 
Color
greenish yellow, greenish white, yellow, light green 
Streak
yellow 
Class
Monoclinic - Prismatic 
Hardness
Collection
Dr. Buford Nichols Collection

Kidwellite

with Beraunite & Rockbridgeite - #BN53055
Locality
Three Oaks Gap, Polk Co., Arkansas, United States 
Formula
NaFe3+9(PO4)6(OH)11·3H2
Availability
Sold
Size
5 x 3.5 x 3.5 cm - Miniature 
Tagged
phosphate  

Globular light green Kidwellite on black, beady-looking and stalatitic Rockbridgeite(?). Amongst all of this are spherical groups of purple Strengite, much of which do not appear in the photos. Along the edges is a perimeter of deep red, bladed Beraunite (or Eleonorite). 


Kidwellite

Formula
NaFe3+9(PO4)6(OH)11·3H2
Crystal System
Monoclinic 
Crystal Habit
Fibrous, Columnar 
Cleavage
Perfect, None, None 
Luster
Silky 
Color
greenish yellow, greenish white, yellow, light green 
Streak
yellow 
Class
Monoclinic - Prismatic 
Hardness
Collection
Dr. Buford Nichols Collection

Kidwellite

with Rockbridgeite - #BN53070
Locality
York mine, Polk Co., Arkansas, United States 
Formula
NaFe3+9(PO4)6(OH)11·3H2
Availability
Available
Price
$60.00
Size
7.5 x 5 x 6 cm - Sm Cabinet 
Tagged
phosphate  

Light green spherical Kidwellite groups to over 5mm on black, botryoidal Rockbridgeite. The Rockbridgeite ID is an assumption. It quite possible be Dufrenite. There is some minor Beraunite. Under the scope you will see several prismatic crystals which have either been coated or replaced by the black stuff. The centers of the Kidwellites all have an unidentified rusty red interior. 


Kidwellite

Formula
NaFe3+9(PO4)6(OH)11·3H2
Crystal System
Monoclinic 
Crystal Habit
Fibrous, Columnar 
Cleavage
Perfect, None, None 
Luster
Silky 
Color
greenish yellow, greenish white, yellow, light green 
Streak
yellow 
Class
Monoclinic - Prismatic 
Hardness
Collection
Dr. Buford Nichols Collection

Phosphosiderite

with Rockbridgeite & Beraunite - #BN53063
Locality
Williams prospect, Coosa Co., Alabama, United States 
Formula
Fe3+PO4·2H2
Availability
Sold
Size
5 x 3 x 3.5 cm - Miniature 
Tagged
phosphate  

Purple spherulites in cavities of phosphate pods mostly composed of Rockbridgeite and Beraunite.


Phosphosiderite

Formula
Fe3+PO4·2H2
Crystal System
Monoclinic 
Crystal Habit
Encrustations, Spherical 
Cleavage
Perfect, Distinct, None 
Luster
Vitreous (Glassy) 
Color
colorless, purple, pink, red, red violet 
Streak
white 
Class
Monoclinic - Prismatic 
Fracture
Uneven 
Hardness
3.5-4 
Collection
Dr. Buford Nichols Collection

Phosphosiderite

with Rockbridgeite - #BN53066
Locality
Williams prospect, Coosa Co., Alabama, United States 
Formula
Fe3+PO4·2H2
Availability
Sold
Size
5 x 2.5 x 3 cm - Miniature 
Tagged
phosphate  

Beaded Phosphosiderite less than 1mm in a grape-like bunches. Colorful.


Phosphosiderite

Formula
Fe3+PO4·2H2
Crystal System
Monoclinic 
Crystal Habit
Encrustations, Spherical 
Cleavage
Perfect, Distinct, None 
Luster
Vitreous (Glassy) 
Color
colorless, purple, pink, red, red violet 
Streak
white 
Class
Monoclinic - Prismatic 
Fracture
Uneven 
Hardness
3.5-4 
Collection
Dr. Buford Nichols Collection

Straczekite

#DO53041
Locality
Union Carbide mine, Wilson Springs, Garland Co., Arkansas, United States 
Formula
(Ca,K,Ba)V8O20·3H2
Availability
Sold
Size
4 x 3.5 x 2 cm - Miniature 
Tagged
vanadium  

Not a phosphate, but for sake of semi-completeness, it is here on this update because it is a good, rare mineral. Straczekite is tar black and crystallizes in plates grouped in curled-up balls. They are quite weird looking actually. You can't find them anywhere else. It's a four-locality mineral.


Straczekite

Formula
(Ca,K,Ba)V8O20·3H2
Crystal System
Monoclinic 
Crystal Habit
Microscopic Crystals, Fibrous 
Cleavage
Perfect, None, None 
Luster
Greasy (Oily) 
Color
greenish black 
Streak
greenish black 
Class
Monoclinic - Prismatic 
Hardness
1-2 
Collection
Don Owens Collection

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