Decrespignyite-(Y)
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| Decrespignyite-(Y) | |
|---|---|
Near perfect formation of (blue) Decrespignyite-(Y) crystals creating botryoidal type formations with a small amount of (grey) Kamphaugite-(Y) | |
| General | |
| Category | Carbonate minerals |
| Formula | Cu(Y, REE)4(CO3)4(OH)5Cl · 2H2O |
| IMA symbol | Dcp-Y[1] |
| Strunz classification | 5.CC.35 |
| Dana classification | 16a.1.11.1 |
| Crystal system | Monoclinic Unknown space group |
| Identification | |
| Color | bright royal blue to pale blue |
| Fracture | none observed |
| Mohs scale hardness | 4 |
| Luster | vitreous, pearly |
| Streak | pale blue |
| Density | 3.64 g/cm3 (measured) 3.645 g/cm3 (calculated)[2] |
| References | [3][4] |
Decrespignyite-(Y) is a copper yttrium rare earth carbonate chloride hydrate;[2]
- With a simple formula of; Cu(Y, REE)4(CO3)4(OH)5Cl · 2H2O[3]
Usually found as single pseudohexagonal platelets, often curved, and regularly measuring 10-50μm in size. It appears as royal blue to turquoise blue in colour, with a pale blue streak, and a pearly to vitreous lustre. Regarded as a supergene mineral which is believed to be formed through by mildly carbonated ground waters precipitating through the ore body. It is often associated with malachite, kamphaugite-(Y), donnayite-(Y) and caysichite-(Y).[2] It is to be further noted that all 'donnayite-(Y)' associated with decrespignyite-(Y) at the Paratoo Copper Mine is very likely to be erroneously named at the locality and is probably alicewilsonite-(YLa).