 |
|
|
Jarosite is both an individual mineral, as well a group name of several similar minerals. Jarosite is the most common member of the group; some of the other rare members include Ammoniojarosite, Argentojarosite, Beaverite, Dorallcharite, Hydroniumjarosite, Natrojarosite, and Plumbojarosite.
Jarosite was first described in 1852 by German mineralogist August Breithaupt in type locality of Barranco Jaroso in the Sierra Almagrera in Southern Spain. In 2004, it was detected by the exploration rover Opportunity on Mars, indicating the possible presence of water that once existed on Mars. |
|
|
Chemical Formula |
KFe3+3(SO4)2(OH)6 |
|
Composition |
Basic hydrous potassium iron sulfate |
|
Color |
Yellow-brown, brown, orange-brown |
|
Streak |
Light yellow |
|
Hardness |
2.5 - 3.5 |
|
Crystal System |
Hexagonal |
Crystal Forms
and Aggregates |
Generally only is small crystals, which are hexagonal or triangular shaped, and may also be tabular or pseudocubic. Also drusy, grainy, as fibrous crusts, in nodules, and in thin, hexagonal scales. |
|
Transparency |
Translucent |
|
Specific Gravity |
2.9 - 3.3 |
|
Luster |
Resinous to adamantine |
|
Cleavage |
2,1 - basal (usually cannot be determined) |
|
Fracture |
Conchoidal, uneven |
|
Tenacity |
Brittle to slightly sectile |
|
In Group |
Sulfates; Hydrous Sulfates |
|
Striking Features |
Crystal habits and color |
| Environment |
Forms through weathering in arid regions as a secondary mineral. |
| Rock Type |
Sedimentary, Metamorphic |
|
Popularity (1-4)
|
3 |
|
Prevalence (1-3)
|
3 |
|
Demand (1-3) |
2 |
|
|
 |
|
|
|
|
|
Jarosite is not an industrially important mineral. However, it is popular among micromount collectors who find this mineral, which is only in small crystals, interesting in shape and color.
|
Jarosite is not a common mineral. It has been found in the Jaroso Ravine in Sierra Almagrera, Spain, the type locality for which it was named after. It is also found in Spain in the La Murta Mine, Castellon. Other European localities for Jarosite are Caldbeck Fells, Cumbria, England; the Clara mine in Rankach, Baden-Wurttemberg, Germany; Huanani, Bolivia; and Sierra Pena Blanca, Chihuahua, Mexico.
In the U.S., Jarosite exists in several localities in Nevada, specifically at the Silver Coin Mine, Valmy, Humboldt Co.; Majuba Hill, Pershing Co.; and the Gilbert District, Goldfield, Esmeralda Co. Other occurrences are Bisbee and Tombstone, Cochise Co., Arizona; the Tintic District, Juab Co., Utah; the Iron Arrow Mine, Chaffee Co., Colorado; and Girard, Burke Co., Georgia. An important Mexican locality for Jarosite is Sierra Peña Blanca, Chihuahua.
|
|
Jarosite's crystal forms combined with its color easily identify it. However, poorly crystallized examples and massive forms of Jarosite may be difficult to distinguish from other minerals, such as Limonite. Jarosite is also indistinguishable from its isomorphous mineral Natrojarosite by ordinary methods.
|
|
|
|
|
|
|
|
Have a question about Jarosite? Visit our Q&A Community and ask the experts!
|
|
|
|
Let us know how we can update this page
(Click for more details)
|
|
We strive for accurate content and locality information. If you feel any of the content is incorrect, or if you feel we are missing vital locality information, please fill out the form below so we can update the site. If you are requesting a locality be added, please only include significant locality occurences for the mineral.
|
 |
| |
|
|
|
|
|
|
|
