Smoky Quartz, Amethyst and Calcite
| ID | 495 | |
|---|---|---|
| Mineral |
Smoky Quartz
Amethyst Calcite |
|
| Location | Las Choyas - Aldama - Chihuahua - Mexico | |
| Fluorescence | LW-UV: close SW-UV: close |
|
| Mindat.org |
View Smoky Quartz information at mindat.org View Amethyst information at mindat.org View Calcite information at mindat.org |
|
Mindat data
| ID | 3689 |
|---|---|
| Long ID | 1:1:3689:0 |
| IMA Status |
0 1 |
| Variety of | 3337 |
| Entry type | 2 |
| Description | A smoky-gray, brown to black variety of quartz that owes its color to gamma irradiation and the presence of traces of aluminum built into its crystal lattice (Griffiths et al, 1954; O'Brien, 1955). The irradiation causes the aluminum Al(+3) atoms that ... |
| Diapheny | Transparent,Translucent |
| Colour | gray, brown, black |
| Hardness (min) | 7.0 |
| Hardness (max) | 7.0 |
| Lustre | Vitreous |
| Crystal System | Trigonal |
| ID | 198 |
|---|---|
| Long ID | 1:1:198:0 |
| IMA Status |
0 1 |
| Variety of | 3337 |
| Entry type | 2 |
| Description | A violet to purple variety of quartz that owes its color to gamma irradiation (Berthelot, 1906) and the presence of traces of iron built into its crystal lattice (Holden, 1925). The irradiation causes the iron Fe(+3) atoms that replace Si in the lattic... |
| Other Occurrences | Very common, in many different environments. The commercially most important occurrences are in volcanic rocks, where amethyst crystals outline former gas cavities. In low and medium temperature hydrothermal veins associated with iron ores. As late overgrowth ("scepter quartz") on quartz in pegmatite and alpine-type environments. |
| Colour | Violet - purple |
| Hardness (min) | 7.0 |
| Hardness (max) | 7.0 |
| Lustre | Vitreous |
| About the name | From Greek "a-methystos", meaning not drunk. |
| Crystal System | Trigonal |
| ID | 859 |
|---|---|
| Long ID | 1:1:859:4 |
| Formula |
Ca(CO3)
|
| IMA Status |
0 1 |
| Other Occurrences | Found in most geologic settings and as a later forming replacement mineral in most other environments in one form or another, it is most common as massive material in limestones and marbles. It forms as chemical sedimentary deposits as limestone, can be regionally or contact metamorphosed into marbles and rarely forms igneous rocks (carbonatites). Also is a common gangue mineral in hydrothermal deposits. |
| Industrial | Mined extensively for a wide variety of uses ranging from lime (cement) to limestone and marble building stones and aggregates, agricultural supplements and optical calcite. |
| Diapheny | Transparent,Translucent |
| Cleavage |
Perfect on |
| Tenacity | brittle |
| Colour | White, Yellow, Red, Orange, Blue, Green, Brown, Gray etc. |
| Hardness (min) | 3.0 |
| Hardness (max) | 3.0 |
| Luminescence | Fluorescent |
| Lustre | Vitreous |
| About the name | Ancient name. Named as a mineral by Gaius Plinius Secundus (Pliny the elder) in 79 from Calx, Latin for Lime. |
| Streak | White |
| Crystal System | Trigonal |
| Cleavage Type | Perfect |
| Fracture type | Conchoidal |
| Morphology | Over 800 different forms have been described. Most commonly as acute rhombohedrons or prismatic with scalenohedral terminations, or combinations of the two. |
| Twinning |
At least four twin laws have been described, the most common being when the twin plane and the composition plane are |
| UV | May be fluorescent under LW UV, mid-range UV or SW UV as well as under X-rays, cathode rays and even sunlight, in a number of colors and shades, commonly an intense red under SW with Mn as an activator (such as at Franklin, New Jersey, USA, and Långban in Sweden. |
| Comment Luster | Pearly on cleavage and {0001}. Can be dull or earthy in chalk variety. |
| shortcode_ima | Cal |
| Group | Calcite Group |
Details
Price: € 35
Dimensions: Not registered
Weight: Not registered
Visibile in overview:
Notes:
| Symbol | Element | |
|---|---|---|
| C | Carbon | |
| Ca | Calcium | |
| O | Oxygen | |
| Si | Silicium |