Editing Kamacite (section)

===Identification===
Kamacite is opaque, and its surface generally displays varying shades of gray streaking, or "quilting" patterns. Kamacite has a metallic luster. Kamacite can vary in hardness based on the extent of shock it has undergone, but commonly ranks a four on the mohs hardness scale. Shock increases kamacite hardness, but this is not 100% reliable in determining shock histories as there are myriad other reasons that the hardness of kamacite could increase.<ref name="Jain Gordon Lipschutz">{{cite journal | journal = Journal of Geophysical Research | volume = 77| issue = 35| pages = 6940–6954| year= 1972| title= Hardness of Kamacite and Shock Histories of 119 Meteorites | last1 = Jain |first1=V. A. |last2=Gordon |first2=R. B. |last3=Lipschutz |first3=M. E.| doi=10.1029/jb077i035p06940| bibcode=1972JGR....77.6940J}}.</ref>

Kamacite has a measured density of {{val|7.9|ul=g/cm3}}. It has a massive crystal habit but normally individual crystals are indistinguishable in natural occurrences. There are no planes of cleavage present in kamacite which gives it a hackly fracture. Kamacite is magnetic, and isometric which makes it behave optically isometrically.

Kamacite occurs with [[taenite]] and a mixed area of kamacite and taenite referred to as [[plessite]].<ref name="Goldstein">{{cite journal|last1=Goldstein|first1=J. I.|title=The formation of the kamacite phase in metallic meteorites|journal=Journal of Geophysical Research|volume=70|issue=24|pages=6223–6232|doi=10.1029/jz070i024p06223|bibcode=1965JGR....70.6223G|hdl=2060/19650024149|year=1965|hdl-access=free}}</ref>

Taenite contains more nickel (12 to 45&nbsp;wt. % Ni) than kamacite (which has 5 to 12&nbsp;wt. % Ni). The increase in nickel content causes taenite to have a face-centered unit cell, whereas kamacite's higher iron content causes its unit cell to be body centered. This difference is caused by nickel and iron having a similar size but different interatomic magnetic and quantum interactions.<ref name="Ramsden">{{cite journal |last1=Ramsden |first1=A. R. |title=Kamacite and taenite superstructures and a metastable tetragonal phase in iron meteorites |journal=The American Mineralogist |year=1966 |volume=51 |pages=1–2, 37}}</ref>

====Tetragonal phase====
There is evidence of a tetragonal phase, observed in X-ray powder tests and later under a microscope. When tested two meteorites gave d-values that could "be indexed on the basis of a tetragonal unit cell, but not on the basis of a cubic or hexagonal unit cell".<ref name="Ramsden" /> It has been speculated to be e-iron, a hexagonal polymorph of iron.