Removed proxy/dead URL that duplicated identifier. | Use this bot. Report bugs. | Suggested by Corvus florensis | #UCB_webform 944/3500
|
dash
Tags: Mobile edit Mobile web edit Advanced mobile edit
|
||
(4 intermediate revisions by 3 users not shown) | |||
Line 12: | Line 12: | ||
| system = [[Cubic crystal system|Isometric]] |
| system = [[Cubic crystal system|Isometric]] |
||
| class = Hexoctahedral (m{{overline|3}}m) <br/>[[H-M symbol]]: (4/m {{overline|3}} 2/m) |
| class = Hexoctahedral (m{{overline|3}}m) <br/>[[H-M symbol]]: (4/m {{overline|3}} 2/m) |
||
| symmetry = '' |
| symmetry = ''Fd{{overline|3}}m'' (no. 227) |
||
| unit cell = a = 8.457 Å; Z = 8 |
| unit cell = a = 8.457 Å; Z = 8 |
||
| color = Black to brownish black |
| color = Black to brownish black |
||
Line 19: | Line 19: | ||
| cleavage = {111}, probably a parting |
| cleavage = {111}, probably a parting |
||
| fracture = Conchoidal |
| fracture = Conchoidal |
||
| mohs = 5. |
| mohs = 5.5–6.5 |
||
| luster = Metallic |
| luster = Metallic |
||
| refractive = ~ |
| refractive = ~2.3 |
||
| opticalprop = Isotropic |
| opticalprop = Isotropic |
||
| birefringence = |
| birefringence = |
||
Line 39: | Line 39: | ||
'''Jacobsite''' is a [[manganese]] [[iron]] [[oxide mineral]]. It is in the [[spinel]] group and forms a [[solid solution]] series with [[magnetite]]. The chemical formula is (Mn,Mg)Fe<sub>2</sub>O<sub>4</sub> or with [[Redox|oxidation states]] and substitutions: |
'''Jacobsite''' is a [[manganese]] [[iron]] [[oxide mineral]]. It is in the [[spinel]] group and forms a [[solid solution]] series with [[magnetite]]. The chemical formula is (Mn,Mg)Fe<sub>2</sub>O<sub>4</sub> or with [[Redox|oxidation states]] and substitutions: |
||
(Mn<sup>2+</sup>,Fe<sup>2+</sup>,Mg)(Fe<sup>3+</sup>,Mn<sup>3+</sup>)<sub>2</sub>O<sub>4</sub>.<ref name=Handbook/><ref name=Webmin>[http://www.webmineral.com/data/Jacobsite.shtml Webmineral data] </ref> |
(Mn<sup>2+</sup>,Fe<sup>2+</sup>,Mg)(Fe<sup>3+</sup>,Mn<sup>3+</sup>)<sub>2</sub>O<sub>4</sub>.<ref name=Handbook/><ref name=Webmin>[http://www.webmineral.com/data/Jacobsite.shtml Webmineral data] </ref> |
||
⚫ | [[File:Jacobsite-d05-134a.jpg|thumb|left|Jacobsite, N'Chwaning Mines, [[Kuruman]], Kalahari manganese fields, [[Northern Cape Province]], South Africa. Size 3.8 x 3.5 x 3.2 cm]] |
||
{{clear left}} |
|||
It occurs as a primary phase or as alteration of other manganese minerals during [[metamorphism]] of manganese deposits.<ref name=Webmin/> Typical associated minerals include [[hausmannite]], [[galaxite]], [[braunite]], [[pyrolusite]], [[coronadite]], [[hematite]] and magnetite.<ref name=Handbook/> It is a [[ferrimagnetic]] substance, which is weakly attracted by a magnet. |
It occurs as a primary phase or as alteration of other manganese minerals during [[metamorphism]] of manganese deposits.<ref name=Webmin/> Typical associated minerals include [[hausmannite]], [[galaxite]], [[braunite]], [[pyrolusite]], [[coronadite]], [[hematite]] and magnetite.<ref name=Handbook/> It is a [[ferrimagnetic]] substance, which is weakly attracted by a magnet. |
||
It was first described in 1869 and named for the Jakobsberg Mine, [[Nordmark, Sweden|Nordmark]], [[Filipstad]], [[Värmland]], [[Sweden]].<ref name=Mindat/> |
It was first described in 1869 and named for the Jakobsberg Mine, [[Nordmark, Sweden|Nordmark]], [[Filipstad]], [[Värmland]], [[Sweden]].<ref name=Mindat/> |
||
⚫ | [[File:Jacobsite-d05-134a.jpg|thumb|left|Jacobsite, N'Chwaning Mines, [[Kuruman]], Kalahari manganese fields, [[Northern Cape Province]], South Africa. Size 3.8 x 3.5 x 3.2 cm]] |
||
==References== |
==References== |
Jacobsite | |
---|---|
![]() | |
General | |
Category | Oxide minerals Spinel group Spinel structural group |
Formula (repeating unit) | iron(II,III) manganese oxide, (Mn,Mg)Fe2O4 |
IMA symbol | Jcb[1] |
Strunz classification | 4.BB.05 |
Crystal system | Isometric |
Crystal class | Hexoctahedral (m3m) H-M symbol: (4/m 3 2/m) |
Space group | Fd3m (no. 227) |
Unit cell | a = 8.457 Å; Z = 8 |
Identification | |
Color | Black to brownish black |
Crystal habit | Disseminated to massive, rarely as octahedral crystals |
Twinning | Spinel law, flattened on {111} or lamellar |
Cleavage | {111}, probably a parting |
Fracture | Conchoidal |
Mohs scale hardness | 5.5–6.5 |
Luster | Metallic |
Streak | reddish black to brown |
Diaphaneity | Opaque |
Specific gravity | 4.76 |
Optical properties | Isotropic |
Refractive index | ~2.3 |
Other characteristics | weakly magnetic |
References | [2][3] |
Jacobsite is a manganese iron oxide mineral. It is in the spinel group and forms a solid solution series with magnetite. The chemical formula is (Mn,Mg)Fe2O4 or with oxidation states and substitutions: (Mn2+,Fe2+,Mg)(Fe3+,Mn3+)2O4.[2][4]
It occurs as a primary phase or as alteration of other manganese minerals during metamorphism of manganese deposits.[4] Typical associated minerals include hausmannite, galaxite, braunite, pyrolusite, coronadite, hematite and magnetite.[2] It is a ferrimagnetic substance, which is weakly attracted by a magnet.
It was first described in 1869 and named for the Jakobsberg Mine, Nordmark, Filipstad, Värmland, Sweden.[3]
This article about a specific oxide mineral is a stub. You can help Wikipedia by expanding it. |
| |||||
---|---|---|---|---|---|
Borates |
| ||||
Carbonates |
| ||||
Oxides |
| ||||
Phosphates |
| ||||
Silicates |
| ||||
Sulfides |
| ||||
Other |
| ||||