Herbertsmithite

Infobox mineral
name = Herbertsmithite
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formula = ZnCu₃(OH)₆Cl₂
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color = Light green, blue-green
habit =
system = Trigonal
twinning =
cleavage = Distinct to good
fracture =
tenacity = Brittle
mohs = 3-3½
luster = Vitreous
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streak = Light green
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density = 3.76
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diaphaneity = Transparent
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Herbertsmithite is a mineral with chemical structure ZnCu₃(OH)₆Cl₂. It is named after the mineralogist Herbert Smith and was first found in 1972 in Chile. The mineral has properties considered, generically, to be of potential use in quantum computing. A polymorph of kapellasite and closely related to paratacamite, is generally found in and around Anarak, Iran, hence its other name, Anarakite. Herbertsmithite is associated with copper mineralizations in syenitic porphyries and granites.

Recent studies at MIT have investigated purified herbertsmithite in a study to determine if it is a new state of matter known as a string-net liquid (see also: string-net). Current research is incomplete, however compelling evidence has raised the possibility that it may be this previously unobserved state of matter. Electrons in herbertsmithite are arranged in a triangular mesh termed a Kagome lattice. Electrons in many lattices form patterns in which neighboring spins point in opposite directions; this requires that looped paths contain even numbers of atoms, so that their spins can always alternate from one to the next. Theory predicts that a Kagome lattice, which contains odd-numbered loops, can support a string-net electronic state.

Herbertsmithite has a vitreous lustre and is fairly transparent with a light-green to blue green color. Herbertsmithite has a Mohs hardness of between 3 and 3.5 and is known to have a brittle tenacity. The crystal's density has been calculated at 3.76 g/cm3.

References

* [http://www.mindat.org/min-26600.html Herbertsmithite] at mindat.org
* [http://webmineral.com/data/Herbertsmithite.shtml webmineral.com] Has information on Herbertsmithite . Accessed March 2007
* [http://www.newscientist.com/article/mg19325954.200?DCMP=Matt_Sparkes&nsref=fourth-state "The universe is a string-net liquid"] . "New Scientist".
* [http://arxiv.org/abs/cond-mat/0610539 Spin Dynamics of the Spin-1/2 Kagome Lattice Antiferromagnet ZnCu3(OH)6Cl2]
* [http://arxiv.org/abs/cond-mat/0610540 Ground state and excitation properties of the quantum kagomé system ZnCu3(OH)6Cl2 investigated by local probes]