Input interpretation
fornacite (mineral) | helmutwinklerite (mineral)
Images
Images
General properties
| fornacite | helmutwinklerite alternate names | furnacite | (none) formula | Pb_2Cu(CrO_4)(AsO_4)(OH) | PbZn_2(AsO_4)_2·2(H_2O) discovery year | 1915 | 1980
Basic properties
| fornacite | helmutwinklerite density | 6.27 g/cm^3 | 5.3 g/cm^3 transparency | transparent | translucent | birefringence | 0.1 | 0.16 luster | vitreous | glassy | vitreous | resinous Mohs hardness | 5/2 | 4.5 streak | greenish yellow | white magnetism | nonmagnetic | nonmagnetic color | green | yellow | olive green | greenish yellow | colorless | sky blue fracture | conchoidal | molar mass | 749.9 g/mol | 651.9 g/mol
Units
Mineral identifiers
| fornacite | helmutwinklerite Strunz ID | VI/F.02-20 | VII/C.31-100 Dana ID | 43.4.3.2 | 40.2.9.2 IMA number | | IMA1979-010 ICSD number | ICSD26828 | ICSD76617
Crystallographic properties
| fornacite | helmutwinklerite crystal system | monoclinic | triclinic crystal class | 2/m | 1 unit cell volume | 776.3 Å^3 (cubic ångströms) | 197.8 Å^3 (cubic ångströms) d-spacing | 2.88 Å (ångströms) | 2.98 Å (ångströms) | 3.31 Å (ångströms) | 3.071 Å (ångströms) | 4.698 Å (ångströms) | 3.279 Å (ångströms) intensity | 100% | 100% | 100% | 100% | 72% | 69% molecules per unit cell | 4 molecules per cell | 1 molecule per cell 2V angle | | 77 π/180 radians≈77° (degrees) refractive indices | 2.14 | 0 | 0 | 0 | 0 | 0 | 1.775 | 1.835 | 1.935 | 0 | 0 | 0 dispersion | strong | moderate | r < v unit cell lengths | 7.91 Å (ångströms) | 5.91 Å (ångströms) | 17.46 Å (ångströms) | 5.606 Å (ångströms) | 5.61 Å (ångströms) | 7.617 Å (ångströms) unit cell angles | 90° (degrees) | 108° (degrees) | 90° (degrees) | 70.19° (degrees) | 69.91° (degrees) | 69.18° (degrees)
Wikipedia summary
Fornacite
Fornacite is a rare lead, copper chromate arsenate hydroxide mineral with the formula: Pb_2Cu(CrO_4)(AsO_4)(OH). It forms a series with the phosphate mineral vauquelinite. It forms variably green to yellow, translucent to transparent crystals in the monoclinic - prismatic crystal system. It has a Mohs hardness of 2.3 and a specific gravity of 6.27.