Difference between revisions of "Salts of oxoacids"
From apm
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Not exactly a salt but related ... | Not exactly a salt but related ... | ||
| − | == | + | == Phosphate minerals == |
[http://en.wikipedia.org/wiki/Phosphate_minerals (wikipedia)] | [http://en.wikipedia.org/wiki/Phosphate_minerals (wikipedia)] | ||
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* Pb<sub>5</sub>(PO<sub>4</sub>)<sub>3</sub>Cl pyromorphite [http://en.wikipedia.org/wiki/Pyromorphite (wikipedia)] - relatively hard for a lead mineral (Mohs 3.5) | * Pb<sub>5</sub>(PO<sub>4</sub>)<sub>3</sub>Cl pyromorphite [http://en.wikipedia.org/wiki/Pyromorphite (wikipedia)] - relatively hard for a lead mineral (Mohs 3.5) | ||
* YPO<sub>4</sub> Xenotime [http://en.wikipedia.org/wiki/Xenotime (wikipedia)] - rare yttrium - high symmetry (tetragonal) - (Mohs 4.5) | * YPO<sub>4</sub> Xenotime [http://en.wikipedia.org/wiki/Xenotime (wikipedia)] - rare yttrium - high symmetry (tetragonal) - (Mohs 4.5) | ||
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| + | == Sulfate minerals == | ||
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| + | [http://en.wikipedia.org/wiki/Sulfate_minerals (wikipedia)] | ||
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| + | Sulfate minerals are generally rather soft with few exceptions. <br> | ||
| + | One of the harder ones is brochantite [http://en.wikipedia.org/wiki/Brochantite (wikipedia)] - (Mohs 3.5-4) | ||
Revision as of 17:40, 9 April 2015
The X-O-X bonds present in those compounds increase the space between the spacially linking X atoms. This lead to a lower density of bonds in cross sections inclusion of bigger voids thus higher porousity. Due to the porousness of these compounds it is harder to get the surfaces flat - figuratively like the surface of a pumice stone. It's impossible to get them as smooth as passivated diamond. [todo: investigate wheter supralubricating bearings can be constructed from these types of diamondoid compounds]
Quartz
Not exactly a salt but related ...
Phosphate minerals
- Especially interesting: Hydoxy- Fluor- & Clorappatite Ca5(PO4)3(F,Cl,OH) - (Mohs 5) - a biomineral
- Lazulite (wikipedia) & Scorzalite (wikipedia) magnesium iron aluminium phosphates - (Mohs 5.5-6)
- Phosphophyllite (wikipedia) - zinc iron phosphate - rather soft (Mohs 3.5)
- Pb5(PO4)3Cl pyromorphite (wikipedia) - relatively hard for a lead mineral (Mohs 3.5)
- YPO4 Xenotime (wikipedia) - rare yttrium - high symmetry (tetragonal) - (Mohs 4.5)
Sulfate minerals
Sulfate minerals are generally rather soft with few exceptions.
One of the harder ones is brochantite (wikipedia) - (Mohs 3.5-4)
