Aluminite and Dolomite
| ID | 35 | |
|---|---|---|
| Mineral |
Aluminite
Dolomite |
|
| Location | Newhaven Cliffs - Newhaven - East Sussex - United Kingdom | |
| Fluorescence | LW-UV: close SW-UV: close |
|
| Mindat.org |
View Aluminite information at mindat.org View Dolomite information at mindat.org |
|
Mindat data
| ID | 154 |
|---|---|
| Long ID | 1:1:154:6 |
| Formula |
Al2(SO4)(OH)4 · 7H2O
|
| IMA Status |
0 1 |
| Other Occurrences | Found as concretionary deposits in Tertiary to Quaternary clays, marls, and lignites, formed by the action of sulfate solutions derived from the decay of pyrite or marcasite on aluminous silicates. Typically in clays or lignites, formed by the reaction of sulfate-bearing solutions from the decomposition of marcasite or pyrite at moderate temperatures with aluminous silicates; as a volcanic sublimate; in sulfur deposits; rarely in caves. |
| Discovery Year | 1807 |
| Diapheny | Translucent,Opaque |
| Cleavage | None |
| Tenacity | fragile |
| Colour | White to yellow, grey; colourless in transmitted light. |
| Hardness (min) | 1.0 |
| Hardness (max) | 2.0 |
| About the name | Named in 1807 for its composition, containing principally aluminium. |
| Streak | White |
| Crystal System | Monoclinic |
| Cleavage Type | None Observed |
| Fracture type | Irregular/Uneven |
| Morphology | As needles and fibers, to 0.1 mm, commonly in reniform, nodular, or spherulitic masses, and as veinlets. |
| Twinning | None noted. |
| shortcode_ima | A |
| Group | Aluminite Group |
| ID | 1304 |
|---|---|
| Long ID | 1:1:1304:4 |
| Formula |
CaMg(CO3)2
|
| IMA Status |
0 1 |
| Other Occurrences | An important sedimentary and metamorphic mineral found as the principal mineral in dolostones and metadolostones, and as an important mineral in limestones and marbles where calcite is the principal mineral present. Also found as a hydrothermal vein mineral, forming crystals in cavities; and found in serpentinites and similar rocks. |
| Industrial | A major source of magnesium, particularly for agricultural and pharmaceutical applications. |
| Discovery Year | 1791 |
| Diapheny | Transparent,Translucent |
| Cleavage |
On |
| Tenacity | brittle |
| Colour | Colourless, white, gray, reddish-white, brownish-white, or pink; colourless in transmitted light |
| Hardness (min) | 3.5 |
| Hardness (max) | 4.0 |
| Luminescence | None |
| Lustre | Vitreous |
| About the name | Named in 1791 by Nicolas Théodore de Saussure in honor of the French mineralogist and geologist, Déodat (Dieudonné) Guy Silvain Tancrède Gratet de Dolomieu [June 24, 1750, Dolomieu, near Tour-du-Pin, Isère, France - November 26, 1801, Château-Neuf, Sâone-et-Loire, France]. de Dolomieu wrote numerous books on observations on geology, notably about the Alps and Pyrenees, in addition to theoretical books about the internal structure of the Earth. He discovered a specimen of what would eventually be called dolomite during his participation in Napoleon Bonaparte's expedition into Egypt in 1798. |
| Streak | White |
| Crystal System | Trigonal |
| Cleavage Type | Perfect |
| Fracture type | Sub-Conchoidal |
| Morphology |
Crystals typically rhombohedral with |
| Twinning |
On {0001}, common with re-entrant angles around the middle edges; on |
| UV | Some types fluoresce white, blue white, creamy yellow, etc. in either SW or LW UV. Manganoan varieties may fluoresce pale pink through intense red, but weaker in long wave. |
| Comment Luster | Usually not vitreous or sub-vitreous |
| shortcode_ima | Dol |
| Group | Dolomite Group |
Details
Price: € 5
Dimensions: Not registered
Weight: Not registered
Visibile in overview:
Notes:
| Symbol | Element | |
|---|---|---|
| Al | Aluminium | |
| C | Carbon | |
| Ca | Calcium | |
| H | Hydrogen | |
| Mg | Magnesium | |
| O | Oxygen | |
| S | Sulfur |