mineral specimens
rare minerals
mineral dealer
systematic minerals
Black Hills minerals
fine minerals
mineral dealer
Dana minerals
IMA minerals
mineral collections
rock and minerals
gem crystal
1 item @ $125.00  

Montgomeryite with Bobdownsite-Whitlockite

#34504

Montgomeryite with Bobdownsite-Whitlockite

#34504
Availability
Sold
Size
10 x 6 x 2 cm - Cabinet 
Formula
Ca4MgAl4(PO4)6(OH)4·12H2O (RRUFF)
Locality
Tip Top mine, Custer Co., South Dakota, United States
Tagged
phosphate

Red to light pink Montgomeryite clusters to 4mm potassium feldspar matrix with minor clear to lilac colored rhombs of Bobdownsite-Whitlockite. Thus far, with the help of RRUFF, tested Whitlockites under the Raman and all have turned out to be Bobdownsite. It is splitting hairs, but until we analyze more, we are going with Bobdownsite as the fluorine anion seems more prevelant. Front and back of this specimen is has good coverage of Montgomeryite .

Montgomeryite

Formula
Ca4MgAl4(PO4)6(OH)4·12H2
Crystal System
Monoclinic 
Cleavage
Perfect, Indistinct, None 
Luster
Vitreous (Glassy) 
Color
colorless, yellowish, white, green, red 
Streak
white 
Class
Monoclinic - Prismatic 
Hardness

Data courtesy of Webmineral.

All photos by Dakota Matrix and are Copyrighted © and may not be used without permission. Copyright © 2021 - Dakota Matrix Minerals, Inc. Privacy | Terms & Conditions | Site Map