This article investigates heat treated, dyed and color enhanced crystals. It is an ongoing project, edited and added to often. I am sure there are many more since I have been away. Do you have a crystal you suspect is heat treated/dyed? Contact me. I will do the research and add to this list.
Education is necessary. Especially when the process was not disclosed. Whether you like them or you don’t, I offer the following information with no prejudice either way. As I always say, “Become self empowered! Find your crystal voice!” and this is my way of helping you along.
So let’s begin…A-F
Agate -An intense or brightly colored Agate (think cobalt blue, bright pink, purple, etc) has been dyed. A tell tale sign is that the color is not consistent. It will look blotchy, uneven or follow the cracks and fractures of the Agate itself.
Aura Quartz is commonly a lower grade Natural Quartz, artificially coated with a ultra-thin metallic layer producing an iridescent sheen. The natural quartz is colorless and clear without the coating. Various Aura Quartz names and the metals that coat them can be found here.
Citrine- if the Citrine is a honey to dark brown in color, it is heat treated Amethyst.
Crackle Quartz is quartz that has been super heated and then dipped in a dye bath. The color is often blotchy, uneven or follow the internal fractures created by the heating process. Usually lower grade quartz is used in this process.
“Fire and Ice” Quartz– uses the same type of process seen in Crackle Quartz. Quartz which has experienced thermal shock. A process that leaves pathways of fractures throughout the body of the quartz often leaving fractures that create fake rainbows. What a lovely way to “dress up” damaged
quartz and charge a fortune, right?
G-M
Gemstones– Ruby, Sapphire, Topaz and others, especially in the gem trade, are heat treated to enhance their colors. They also can be synthesized (man made/lab).
Green Quartz (China) is Quartz that is super heated with chromium.
Green Amber is often manufactured Amber or Copal. The process includes heat treating the Amber or Copal in an autoclave or through a radiation process. There are blue and green Amber, which are more of a reflected light than a true color. See the note and references below for more information.
Notes: Blue and green amber is found only in the Dominican Republic. This blue (or green) color is only seen in reflected light. In transmitted light it will show a more common amber color (yellow, orange, red). The color of the blue and green gems is from fluorescence of UV and violet light from natural sunlight.
Howlite– Any Howlite that has intense color (turquoise, blue, purple, pink, etc) is dyed. Much of the turquoise dyed Howlite is passed off as real turquoise.
Mystic Quartz has some similarities to aqua aura quartz. Aqua aura are natural quartz crystals coated with various metals. Mystic quartz is cut quartz which has been coated with a ultra-thin layer of metallic titanium on the pavilion faces.
Obsidian!
Obsidian– There has been an influx of Chinese minerals into the metaphysical and geological communities that needs to be addressed. Theses brightly colored Obsidian are all over the place! As with all things, take what resonates for you and leave the rest.
Many of the pieces coming out of China can be one of three things:
- They are legitimate minerals and crystals mined in China, like Fluorite
- They are polished or tumbled in China due to the cheap labor in which to do so.
- Or they are MANUFACTURED/created/Lab enhanced in China
These “Obsidian” pieces more often than not fall into #3 above. The description reads:
Asian Rare Quartz Crystal or Blue Obsidian Stone Ball Natural or Natal Feng Shui Crystals Sphere.
These NEW! or RARE! brightly colored Obsidian are nothing more than slag glass with color introduced into the process.
Brightly colored Cobalt Blues, Emerald Greens, Rich Reds, Golden Yellows, and deep Purples are a few of the varieties. They are all glass, more often than not, flawless and clear, but mis-marketed/identified as Obsidian (an amorphous volcanic rock).
Much of the Obsidian on the market is glass with color introduced. The dark green is marketed as Helenite or Obsidianite, The Blue as Cobalt Blue. The Lighter Green as Aqua Green or Hawaiian Blue/Green, Purple, Red as Strawberry or Cherry….you get the idea.
O-T
Ouro Verde Quartz is composed of quartz crystals that have been bombarded with Gamma Rays.
Peacock Ore is Chalcopyrite that has been subjected to an acid wash and is often misidentified as
Bornite. True Chalcopyrite is a brassy metallic gold in color.
Sea Sediment Jasper– According to a reliable, trustworthy source, Sea Sediment Jasper is white brecciated Jasper that has been dyed.
Siberian Blue Quartz is lab grown quartz colored by cobalt.
Siberian Green Quartz has been regrown in Russia from natural Quartz in combination with chemicals to produce its intense color.
Tanzanite is a gemmy variety of Zoisite. Most all Tanzanite on the market has been heat-treated to produce an intense blue to blue violet coloring.
References
My personal and continuing research via databases and other geology information.
http://www.mindat.org
http://www.gemdat.org