 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|||||||||||||||||||||
 |
 |
 |
 |
 |
 |
 |
 |
 |
|
|||||||||||||
 |
 |
 |
 |
 |
 |
|
||||||||||||||||
 |
 |
 |
 |
|
||||||||||||||||||
 |
 |
 |
 |
|
||||||||||||||||||
 |
 |
 |
|
|||||||||||||||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|||||||||||||||||||||
|
|
|
|
|
|
|
|
|
|
|||||||||||||
|
|
|
|
|
|
|
||||||||||||||||
|
|
|
|
|
||||||||||||||||||
|
|
|
|
|
||||||||||||||||||
|
|
|
|
|||||||||||||||||||
Mg5(CO3)4(OH)2.5H2O
Monoclinic?
 |
|
|
 |
|
|
| Figure 23-21. Hemispherical aggregate of dypingite crystals. Field of view is 0.2 mm in maximum dimension. | ||
|
Dypingite, a magnesium carbonate hydroxide hydrate mineral, was identified by Dunn (1979c) from the north orebody at Sterling Hill, but has not been reported from Franklin. It occurs as 0.5 mm hemispherules composed of flattened crystals (Figure 23-21) and is bright white with a pearly luster. It was verified using X-ray powder diffraction methods, a microprobe determination of Mg as the only detectable cation, and a positive acid test for carbonate. The mean index of refraction is n = 1.515. Sterling Hill dypingite is fluorescent in ultraviolet, with a blue color in both longwave and shortwave.
The distribution of dypingite spherules on matrix surfaces is not entirely random; they form meandering chains resembling linked colons (:::::::). The pattern of these chains is apparently not related to grain boundaries of the underlying franklinite and willemite matrix minerals and may have been inherited from a now-dissolved precursor.
|
|
|||
|
|
||||
|
||||
| Copyright © 1995 by Pete J. Dunn |
Website
by Herb Yeates
|
|||
|
|
|
|||
|
Link
to homepage
|
||||
|
This
page created: January 11, 2001 |
||||
|
|
|
|||
