Chalcanthite from Local Planet Mine, Arizona USA
Although it is only a small specimen, the crystal structure and bright blue colour of this Chalcanthite are fantastic.
Chalcanthite in individual crystals are very rare in natural form, therefore there are a lot of crystals synthetically grown from copper sulphate solutions available on the market. This one, however, is natural. If a Chalcanthite crystal looks too good to be natural, it probably is, as good natural crystals are very hard to come by.
The largest deposit of chalcanthite occurs in Chuquicamata, Chile while many other copper deposits are found in the southwestern parts of the USA.
Caution: Crystal specimens can easily be grown synthetically, and, as such, there is a concern that disreputable mineral dealers could present a specimen to an unknowing person as natural when it’s not. It is recommended that you deal with reputable dealers that you have dealt with in the past when purchasing this mineral
This specimen was purchased from Greg at Blue Gems at the 2013 Central Coast Gem Festival.
Chemical Formula: CuSO4 · 5H2O
Collection ID #: JG0019
Colour: crystals are a greenish-blue, light to sky blue
Acquisition Date: 12th October 2013
Crystal System: Triclinic
Lustre: Vitreous, silky, dull
Dimensions: 15mm x 20mm x 18mm
Locale: Local Planet Mine. Santa Maria Dist – Buckskin Mountains – La Paz County, Arizona, USA.
Rarity of Mineral