Hapkeite is a

mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2 ...

discovered in the Dhofar 280 meteorite found in 2000 in

Oman Oman ( ; ar, عُمَان ' ), officially the Sultanate of Oman ( ar, سلْطنةُ عُمان ), is an Arabian country located in southwestern Asia. It is situated on the southeastern coast of the Arabian Peninsula, and spans the mouth of ...

on the Arabian peninsula. The meteorite is believed to originate from the

Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

; specifically, it appears to be a fragment of lunar highland

breccia Breccia () is a rock composed of large angular broken fragments of minerals or rocks cemented together by a fine-grained matrix. The word has its origins in the Italian language, in which it means "rubble". A breccia may have a variety of ...

. Hapkeite's composition is of

silicon Silicon is a chemical element with the symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic luster, and is a tetravalent metalloid and semiconductor. It is a member of group 14 in the periodic ta ...

and

iron Iron () is a chemical element with Symbol (chemistry), symbol Fe (from la, Wikt:ferrum, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 element, group 8 of the periodic table. It is, Abundanc ...

, and it is similar to other silicon-iron minerals found on

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

. An impact on the Moon is thought to have launched the partially molten or vaporized material into orbit. Due to its 1:2 composition of silicon-iron, hapkeite was given the

chemical formula In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbol ...

Fe₂ Si. It occurs as opaque, yellowish to silvery microscopic isometric crystals. It is named after Bruce Hapke, who predicted the presence and importance of vapor-deposited coatings on lunar soil grains (

space weathering Space weathering is the type of weathering that occurs to any object exposed to the harsh environment of outer space. Bodies without atmospheres (including the Moon, Mercury, the asteroids, comets, and most of the moons of other planets) take on ...

). Beside hapkeite, other natural iron silicide minerals include gupeiite, naqite,

linzhiite Linzhiite is an iron silicide mineral with the formula FeSi2. It was discovered in the 1960s in Donetsk Oblast in Soviet Union, and named ferdisilicite, but was not approved by the International Mineralogical Association. It was later rediscov ...

, luobusaite, suessite,

xifengite Xifengite ( Fe5 Si3) is a rare metallic iron silicide mineral. The crystal system of xifengite is hexagonal. It has a specific gravity of 6.45 and a Mohs hardness of 5.5. It occurs as steel gray inclusions within other meteorite derived nickel i ...

, and zangboite.

References

Space weathering on airless planetary bodies: Clues from the lunar mineral hapkeite 2004 PNAS
{{Meteorites Iron(II) minerals Meteorite minerals Cubic minerals Minerals in space group 221 Native element minerals

See also

References