Anyways, I know that turquoise gets dyed into all sorts of crazy
colours, like green and purple.
Not generally, no. Lesser quality turqoise sometimes gets dyed to a
better blue, but actual turqoise is not usually more saleable if dyed
green, or ghod forbid, purple. However, there are any number of other
cheap stones that DO get dyed all sorts of colors, and some of them
are now and then (or more often) misrepresented as turqoise.
Green turqoise does indeed exist, at least to some degree. If you’ve
got intense emerald green, it’s dyed and most likely not turqoise.
But lower quality turqoise often “ages” with time from an original
shade of blue to green, as the copper content that gives it the
desired blue colors changes oxidation states (or something like
that). It’s common to find old turqoise that was treated by simply
oiling or waxing it to intensify the color, that has now over time
changed color to a greenish blue or bluish green. A real pure green
is not likely to be turqoise. But a malachite sort of green is
certainly common enough. The color, like most of the blues in
tuqoise, tends to the less intense. If you’ve got a vibrant intense
green that rivals fine imperial jade, or a green to make an emerald
or tsavorite jealous, then you can rest assured that it’s not
turqoise is one of those minerals which does not owe it’s color to
some slight and variable impurity in an otherwise colorless mineral.
The blue / green color is due to copper, an essential and intrinsic
part of the chemistry of the mineral. Now, the exact state of that
copper content varies, as does the degree to which turqoise is dense
and pure rather than mixed with other minerals, so there’s the wide
variation in quality. But turqoise is blue or greenish blue due to
the copper content in it. If it’s not within that "copper caused"
range of colors, then it’s not turqoise. And that copper does limit
just what sorts of other colors you could dye it to.
Nevertheless, you’ll find sellers calling all sorts of other
minerals with that sort of feel and color range turqoise. It’s not
because there’s any sort of gemological similarity to turqoise, but
simply because it’s easier to sell dyed howlite, or dyed something
else, as turqoise, than it is to be honest and call something a cheap
imitation that nevertheless looks nice, or to even actually call such
materials by their actual mineral name (if the dealer even knows
The range of colors and materials that get sold as turqoise these
days begins to approach the degree of casual attitude that surrounded
calling smokey quartz, “smokey topaz” at one time. Like the smokey
quartz, which is not any form of topaz, many of the materials called
"turqoise", have little relationship to that mineral other than a
vague visual resemblance, or often, not even that if a different
Another good example is “red coral”. Go to any gem or bead show and
try to find true gem quality red coral. You’ll find lots of stuff
offered. Reputable dealers will admit it’s dyed. Some might also
admit that the stuff is “sea bamboo” or some other material, not even
coral. But you’ll find enough of them who knowingly or not, call the
stuff red coral, even though it’s not. I’ve seen everything from dyed
limestone (or something like it. Not sure) to glass, sold as coral.
In among all that junk, there will be some true coral. Most tends
more to orange colors, but a bit can still be found that’s more red.
Some dyed, some not. Usually small sizes or little branch shaped
things… But seperating out the real from the junk? Not easy.
Turqoise gets about the same treatment. Lots of junk offered with the
name. Not so much that actually deserves the name.