- Agardite
Agardite is a mineral group consisting of "agardite-(Ce), agardite-(Nd), agardite-(La), and agardite-(Y)". They comprise a group of hydrous
calcium ,copper arsenate minerals which contain variable amounts of the rare elementscerium ,neodymium ,lanthanum andyttrium as well as trace to minor amounts of otherrare earth element s. The general formula is (Ce,La,Nd,Y,Ca)Cu6(AsO4)3(OH)6·3(H2O). They form needle-like yellow green crystals in the hexagonalcrystal system . TheMohs hardness is 3 to 4 and the specific gravity is 3.72.They were first described in 1970 in the
Black Forest ,Germany . They were named afterJules Agard , a Frenchgeologist .References
* [http://www.mindat.org/min-48.html Mindat.org]
* [http://www.webmineral.com/data/Agardite-%28Ce%29.shtml Webmineral data]
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