Fletcherite Explained

Fletcherite
Category:Sulfide mineral
Thiospinel group
Spinel structural group
Imasymbol:Ftc[1]
Strunz:2.DA.05
System:Cubic
Class:Hexoctahedral (mm)
H–M Symbol: (4/m 2/m)
Symmetry:Fdm
Unit Cell:a = 9.520 Å; Z = 8
Color:Steel gray, creamy white in polished section
Habit:Minute subhedral to euhedral crystals typically enclosed within other sulfide minerals
Mohs:5
Luster:Metallic
Diaphaneity:Opaque
Gravity:4.76 calculated
Polish:Good polish with moderate reflectivity
Opticalprop:Isotropic
References:[2] [3] [4] [5]

Fletcherite is a rare thiospinel sulfide mineral with formula . It is an opaque metallic steel gray mineral which crystallizes in the cubic crystal system. It is a member of the linnaeite group.

It was first described in 1977 for an occurrence in the Fletcher Mine, Viburnum Trend (New Lead Belt), near Centerville, Reynolds County, Missouri.[3] [2]

It occurs as a dissemination within copper sulfide minerals in mineralization replacing dolomite at the type locality in the Fletchermine where it is associated with vaesite, pyrite, covellite, chalcopyrite, bornite and digenite. In an occurrence in Kalgoorlie, Australia it is found in black slate associated with pyrrhotite.[2]

Notes and References

  1. Warr. L.N.. 2021. IMA–CNMNC approved mineral symbols. Mineralogical Magazine. 85. 3. 291–320. 10.1180/mgm.2021.43. 2021MinM...85..291W. 235729616. free.
  2. http://www.handbookofmineralogy.org/pdfs/fletcherite.pdf Handbook of Mineralogy
  3. http://www.mindat.org/min-1557.html Mindat
  4. http://webmineral.com/data/Fletcherite.shtml Webmineral data
  5. 10.2113/gsecongeo.72.3.480. Fletcherite, Cu(Ni,Co)2S4, a new thiospinel from the Viburnum Trend (New Lead Belt), Missouri. Economic Geology. 72. 3. 480–486. 1 May 1977. Craig. J. R.. Carpenter. A. B..