Treated Citrine from Minas Gerais, Brazil
Citrine is probably one of the most talked about minerals going around. Is it natural, is it heat treated and does it matter!?
From an aesthetic point of view, the golden points on a citrine cluster can look amazing and from a chemical formula point of view, it is still a variety of quartz (SiO2).
The earth naturally creates citrine with a geothermal heat source; from within the mantle by heating amethyst or smoky quartz which gives it a lovely golden colour. When a piece of dull amethyst or smoky quartz is heat treated, it is mimicking the process that occurs naturally, natural citrine is a much lighter hue.
It is sometimes hard to tell if a specimen has been heat-treated, as with the heat-treated specimen you see here, the colour will be most concentrated at the tips but white at the base. Heat-treated citrine can be kind of crumbly and break apart easily since heating the specimens at the temperature necessary does seem to weaken the stability of the crystals. I have quite a few specimens of natural Australian citrine from Torrington in the collection, check out that page to see the difference in colour.
A classic locality for natural Citrine that is already exhausted is Olkhovka in the Northern Ural Mountains of Russia. Most of the citrine that comes from Brazil will be heat-treated amethyst.
I acquired this specimen back in 2008 from GEO Discoveries, a mineral and fossil shop located in West Gosford on the NSW Central Coast.
Chemical Formula: SiO2
Collection ID #: JG0036
Colour: Dark yellow/golden, orange
Acquisition Date: 4th June 2008
Crystal System: Hexagonal
Dimensions: 130mm x 88mm x 37mm
Locale: Unknown locality for this specimen. If I were to guess where this specimen came from, I would say Minas Gerais, Brazil.
Rarity of Mineral