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Rare Minerals

Sunday, 16 April 2023 06:00 PM

Introducing the "Rare Minerals" gallery which is part of our New Additions galleries. This gallery contains mineral specimens for sale including barysilite, ferri-katophorite, geffroyite, kolwezite, lepidolite, and mckelveyite-(y) and more from places like Parker Shaft, Franklin, Sussex Co., New Jersey, United States, Kipawa alkaline complex, Quebec, Canada, San Miguel mine, Moctezuma, Sonora, Mexico, Mupine mine, Kamoto, Kolwezi dist., DR Congo, Harding mine, Taos Co., New Mexico, United States, and Mont Saint-Hilaire, Montérégie, Québec, Canada.

Barysilite

with Willemite - #BAC61454
Locality
Parker Shaft, Franklin, Sussex Co., New Jersey, United States 
Formula
Pb8Mn(Si2O7)3 
Availability
Sold
Size
1 x 0.7 x 0.3 cm - Thumbnail 

Lilac, platy Barysilite with golassy light green Willemite. It is an excellent specimen, for this fairly rare mineral usually coveted by Franklin collectors.


Barysilite

Formula
Pb8Mn(Si2O7)3 
Crystal System
Trigonal 
Crystal Habit
Massive - Lamellar 
Cleavage
Perfect, None, None 
Luster
Adamantine 
Color
white, gray 
Streak
white 
Class
Trigonal - Hexagonal Scalenohedral 
Hardness
Collection
William & Anne Cook Collection

Ferri-Katophorite

#61471
Locality
Kipawa alkaline complex, Quebec, Canada 
Formula
Na(CaNa)(Mg4Fe3+)(AlSi7O22)(OH)2 
Availability
Sold
Size
8 x 5.5 x 5 cm - Sm Cabinet 

Large, green, blocky crystals of Ferri-katophorite with Fluorite. 


Geffroyite

#BAC61507
Locality
San Miguel mine, Moctezuma, Sonora, Mexico 
Formula
(Cu,Fe,Ag)9Se8 
Availability
Available
Price
$75.00
Size
2.3 x 2 x 1.4 cm - Thumbnail 
Tagged
copper , selenium , silver  

Silvery crystal grains to 0.5mm and in aggregates to around 2mm. The Geffroyite is scattered throughout the matrix not just the arrowed areas.


Geffroyite

Formula
(Cu,Fe,Ag)9Se8 
Crystal System
Isometric 
Luster
Metallic 
Color
bronze brown 
Class
Isometric - Hexoctahedral 
Hardness
2.5 
Collection
William & Anne Cook Collection

Kolwezite

#BAC61450
Locality
Mupine mine, Kamoto, Kolwezi dist., DR Congo 
Formula
CuCoCO3(OH)2 
Availability
Available
Price
$275.00
Size
7.5 x 5.5 x 2.5 cm - Sm Cabinet 
Tagged
carbonate , copper , cobalt  

A large vug 3 x 1.5cm filled with fuzzy or velvety looking green Kolwezite. In-hand the Kolwezite is more of an olive color. Exceptional specimen for a fairly rare mineral found in basically six worldwide deposits.


Kolwezite

Formula
CuCoCO3(OH)2 
Crystal System
Triclinic 
Crystal Habit
Nodular, Encrustations 
Luster
Vitreous (Glassy) 
Color
beige brown, green, black 
Streak
beige 
Class
Triclinic 
Hardness
Collection
William & Anne Cook Collection
Mineralpedia
View Kolwezite
On Dakota Matrix
Previously Sold Kolwezite
On Dakota Matrix
Other Available Kolwezite
WebMineral
View Kolwezite
Mindat
View Kolwezite

Lepidolite

#AH58895
Locality
Harding mine, Taos Co., New Mexico, United States 
Formula
K(Li,Al)3(Si,Al)4O10(F,OH)2 
Availability
Sold
Size
7 x 6 x 4.5 cm - Sm Cabinet 

Pretty purple "books" of Lepidolite to 7mm in Quartz matrix.


Lepidolite

Formula
K(Li,Al)3(Si,Al)4O10(F,OH)2 
Crystal System
Monoclinic 
Crystal Habit
Platy, Foliated, Massive 
Cleavage
Perfect, None, None 
Luster
Vitreous - Pearly 
Color
colorless, gray white, lilac, yellowish, white 
Streak
white 
Class
Monoclinic 
Fracture
Uneven 
Hardness
2.5-3 
Collection
Arnold G Hampson Collection

Mckelveyite-(Y)

#BAC61458
Locality
Mont Saint-Hilaire, Montérégie, Québec, Canada 
Formula
NaBa3(Ca,U)Y(CO3)6·3H2
Availability
Available
Price
$125.00
Size
4 x 3 x 2 cm - Miniature 
Tagged
carbonate , REE mineral  

Interesting yellowish crystals forming saucer-like stacked groups to 1mm in Albite and Phlogopite matrix.


Mckelveyite-(Y)

Formula
NaBa3(Ca,U)Y(CO3)6·3H2
Crystal System
Monoclinic 
Crystal Habit
Pyramidal 
Cleavage
Indistinct, None, None 
Luster
Vitreous (Glassy) 
Color
yellow, black, greenish gray, white, gray 
Streak
white 
Class
Monoclinic - Domatic 
Hardness
3.5-4 
Collection
William & Anne Cook Collection

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