 |
Chemical Formula | BaCO3 |
|
Composition | Barium carbonate |
|
Color | White, cream, grayish-white, and pale yellow |
|
Streak | White |
|
Hardness | 3 - 3½ |
|
Crystal Forms and Aggregates |
(Orthorhombic) Crystals are always twinned, most commonly in pseudohexagonal trillings that are bipyramidal, resembling bipyramidal hexagons. Crystals may also be elongated pseudohexagonal trillings that are not bipyramidal, and are usually scepter shaped. Also occurs fibrous, grainy, platy, mammilary, columnar, crusty, and massive. |
|
Transparency | Transparent to translucent |
|
Specific Gravity | 4.3 - 4.6 |
|
Luster | Vitreous |
|
Cleavage | 3,1 - prismatic |
|
Fracture | Uneven |
|
Tenacity | Brittle |
|
Other ID Marks | Fluorescent whitish-blue. |
|
In Group | Carbonates ; Aragonite group |
|
All About | Witherite is a rare mineral, primarily since
it easily alters
to Barite. It alters when sulfuric acid from
sulfide minerals dissolves the Witherite and the
sulfur combines with the barium and forms Barite (BaSO4).
However, in some localities, such as Hardin Co.,
Illinois, it occurs in relative abundance, as new
specimens are formed from Calcite (CaCO3) that lose
calcium to barium, thus forming Witherite (BaCO3). Thin, long crystals and aggregates of Witherite should be handled carefully, as they are fragile and easily damaged. |
|
Uses | Witherite is an ore of barium in areas where large enough quantities can be obtained. It is also used in the production of glass. Specimens available to collectors are uncommon, and are in large demand by mineral collectors. |
|
Striking Features | Heaviness and hardness |
|
Complex Tests | Soluble and slightly effervescent in cold, diluted, hydrochloric acid, and soluble in sulfuric acid. |
|
Popularity (1-4) | 3 |
|
Prevalence (1-3) | 3 |
|
Demand (1-3) | 1 |
|
Distinguishing Similar Minerals |
Strontianite - lighter in weight (3.7) Aragonite - lighter in weight (2.9 - 3.0) Cerussite - heavier (6.5 - 6.6), exhibits better cleavage Calcite - lighter in weight (2.7) |
|
Commonly Occurs With |
Barite, Fluorite, Calcite, Galena, Sphalerite |
|
Noteworthy Localities |
There are not many localities for this mineral. Well formed crystals and crystal groupings occur in England at Alston Moor and the Nentsberry Haggs Mine, Cumberland, and at Hexam, Northumberland. It was also reported in Tsumeb, Namibia. There is only one region in North America which is a good producer of this mineral, which is the area of the Fluorite mines in Hardin Co., Illinois. Small deposits also exist in El Portal, Mariposa Co., California, Castle Dome District, Yuma Co., Arizona, and in Canada at Thunder Bay, Ontario. |
|
Picture Icon Links |
Sorry. No Images currently available. |
|
Picture Links | Sorry. No Images currently available. |
