New Caledonia
Scott 473
30 francs
17 Mar 1982
| Rock Name: | Anorthosite |
| Composition: | A rock almost entirely composed of plagioclase, a subgroup of the feldspar group of minerals. The plagioclase feldspars form a series from sodium aluminosilicate to calcium aluminosilicate, with the members of the group having varying amounts of sodium and calcium. |
| Nomenclature: | Named after the Greek words an and orthos which mean "not" and "upright" respectively because plagioclase forms obliquely-shaped crystals. |
| Industrial Uses: | Crushed stone, building material. |
| Additional Notes: | Anorthosite is an igneous rock formed beneath the surface of the earth. Its primary constituent, plagioclase, is one of the most common rock-forming minerals. |
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Anorthosite (Feldspar); Nephrite (Jade); Serpentine New Caledonia Scott 473 30 francs 17 Mar 1982 |
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| The stamp shows a polished slab of material. | |
| http://mineralstamps.rbnet.net/anorthosite.htm | Philatelic Mineralogy | Copyright © 1997-2010 by Richard Busch |