Dachiardite-K
Rare zeolite-group mineral From Wikipedia, the free encyclopedia
Dachiardite-K is a rare zeolite-group mineral with the formula K4(Si20Al4O48)•13H2O.[4][3] It is the potassium-analogue of dachiardite-Ca and dachiardite-Na, as suggested by the suffix "-K".[5] [2] Dachiardite honors Italian geologist and mineralogist Antonio D'Achiardi.
| Dachiardite-K | |
|---|---|
| General | |
| Category | Zeolite group, tectosilicate |
| Formula (repeating unit) | K4(Si20Al4O48)·13H2O |
| IMA symbol | Dac-K[1] |
| Crystal system | Monoclinic Unknown space group |
| Unit cell | a = 18.67, b = 7.51 c = 10.23 [Å], β = 107.79° (approximated) |
| Identification | |
| Color | Snow-white |
| Crystal habit | Needle-like crystals in spherical aggregates |
| Cleavage | (100), perfect |
| Fracture | Stepped across |
| Tenacity | Brittle |
| Mohs scale hardness | 4 |
| Density | 2.18 (measured), 2.17 (calculated; approximated) [g/cm3] |
| Optical properties | Biaxial (+) |
| Refractive index | nα=1.48, nβ=1.48, nγ=1.48 (approximated) |
| Pleochroism | No |
| 2V angle | 65o (measured) |
| Dispersion | Distinct |
| References | [2][3] |
Occurrence and association
Dachiardite-K was discovered in opal-chalcedony veins in Eastern Rhodopes, Bulgaria. It is associated with barite, calcite, clinoptilolite-Ca, clinoptilolite-K, celadonite, dachiardite-Ca, dachiardite-Na, ferrierite-K, ferrierite-Mg, ferrierite-Na, mordenite, and smectite.[3]
References
Wikiwand - on
Seamless Wikipedia browsing. On steroids.