Difference between revisions of "Graphite"
(→Uses) |
(Undo revision 8474 by 203.126.25.170 (Talk)) |
||
Line 8: | Line 8: | ||
Graphite occurs on Earth in [[igneous rock|igneous]] and [[metamorphic rock]], sometimes as metamorphosed [[coal]]. It can also be found in [[limestone]]. Some [[meteorites]] contain graphite. | Graphite occurs on Earth in [[igneous rock|igneous]] and [[metamorphic rock]], sometimes as metamorphosed [[coal]]. It can also be found in [[limestone]]. Some [[meteorites]] contain graphite. | ||
− | + | ==Uses== | |
+ | * [[Refractory]] | ||
==Open issues== | ==Open issues== |
Revision as of 05:16, 9 March 2013
Graphite is a form of high-purity carbon which occurs on Earth as a mineral. It can also be artificially produced from silicon carbide.
Coke and charcoal are not as pure as graphite because, while the carbonizing process does boil off volatiles in their production, non-volatile ash remains.
Physical characteristics
Graphite has a hardness of 1 to 2 on Mohs' scale, a black streak, a lustre varying from metallic to dull and earthy, a hexagonal crystal system and specific gravity between 2.1 and 2.23.[1]
Occurence
Graphite occurs on Earth in igneous and metamorphic rock, sometimes as metamorphosed coal. It can also be found in limestone. Some meteorites contain graphite.
Uses
Open issues
- How common are graphitic rocks on Mars?
- How common are graphite-containing meteorites on Mars?
References
- ↑ B. Cairncross - Field guide to rocks and minerals of Southern Africa 2004. ISBN 978-1-86872-985-2 p. 123