| TigerSoft News Service 3/29/2008
Visit our www.tigersoft.com
by William Schmidt, Ph.D.
(C) 2008 All rights reserved.
Beautiful Colors for Your
Enjoyment. See also our American Turquoise: A
Journey through Native Blues.
HARLEQUIN BLACK OPALS - By William
Schmidt, Ph.D. - www.tigersoft.com
Northern lights? Fireworks?
A magic mushroom trip? No, harlequin opals!
Each offers a unique and phenomenal light-show. They bear little resemblance to
much more common, plainer cousins, the ordinary white opals that most US jewelers
offer. When first introduced to England in the late 19th century, harlequin opals
even accepted as opals, they are too gaudily bright and colorful. But they soon took
world's breath away. Viewed from any side, the best black opals send out
light, brilliant ruby-reds, deep, deep blues, glorious purples as well as burning yellows
lush greens. They stun the visual senses. No other gemstone displays the whole
Their shafts of light are so big and bold. Sometimes they form a checkerboard pattern.
They may be may be full opals. Or they may be more affordable doublets or triplets.
wearing a harlequin must be ready for lots of compliments, steady gazes and even offers to
buy her harlequin right there and then. They are not bad luck. Opals simply should
out of direct sunlight, away from extreme cold and occasionally placed in water, so as not
become overly dry and fracture.
99.9% of the brightest colored and most lustrous opals come from only
two places in
the entire world: Lightning Ridge in New South Wales and Mintabie in South
Top quality opals sell for more than $30,000 US per carat.
My visit to the San Diego Gem Faire in April 2008 inspired this write-up. I saw more
opals in 30 seconds that I had ever seen, even though wherever I go I always look for
selling them. They were extraordinary. The man who mined them was kind enough
encourage my interest. Below are some of his opals. Here is his
I saw the opal just below, up close and personal. It is easily worth $250,000. Every
in perspective, radiates new beams of colors. Gazing at it, I felt like I had taken
to a faraway galaxy.
Ebay $49,999 - 36 carats 36 mm x
23 mm X 7 mm - Lightning Ridge "semi-black"
Ebay $45,995 - 31 carats 31 mm x
24 mm X 5 mm -
This is the land they come from.
It is the glow under-ground that often reveals the opals to miners. Special
can find opals more easily.
Australian Black Opals
These stone's spectrum
of colors change as light "plays off the regimented layers of sub-microscopic spheres
the basic structure of opal. In the best examples, dramatic splashes of color are
producing a wide range of patterns....he finest BLACK OPAL in the world comes from
Australia in New
South Wales. It is the RAREST of all opals and can sell for millions of dollars or more.
of black opal is the most prized ! Black Opal also comes in a "crystal form" but
very dark background
color, it may not have any solid black backing visible - in some cases may be double sided
held up to light
you may be able to see through it thus "crystal"... Because of the curious
nature of opal formation,
it is possible
for a variety of organic forms to be systematically replaced by opal bearing fluids that
the object during
the replacement or fossilization process. Shell and other forms of plant life ( and even
can be opalized
in a slow, methodical process, that reproduces the shape of the original life form in both
"common" opals. The
uniqueness of these opals, familiar to the ancient seascape of Australia, has been
mimicked in a
highly transparent opal exhibiting any combination of colors across the spectrum but
of color, like the sea it started with. The desirability of any example of opal
replacement is dependent
on a combination
of factors including shape, form, color, completeness and especially the brightness or
quality of the
material. The patterns can exhibit broad flashes, small flashfires, speckles of color or
Some commercial sites: http://www.aussietreasurechest.com.au/shopdisplayproducts_homepage.asp?id=44
Australian Boulder Opals
Opals. These are found only in Queensland.
They are formed from silicon diozide and
other minerals that have seaped into the fissures of ironstone. The
cutter must always take a little of this natural
ironstone when extracting a gemstone. This gives the dark overall
colour which does not detract from the Boulder
Opal. When little or no ironstone appears in the face of Boulder Opal, the
price of Boulder equals that of very
fine Black Opals. The natural occurrence of Boulder allows for particularly
interesting shapes which in the hands
of a creative jeweller makes for stunning creations.
When the opal is mixed through the boulder ironstone, it is also called
"matrix opal." Hardness ranges between
5.5 and 6 on the Mohs
scale. Boulder opal is very durable due to the ironstone backing the opal forms
Because water content within the opal is very low it almost never cracks or crazes
as it ages.
"During the 1980s,when the super-strong yen pushed black opal prices to levels beyond
the reach of the rest of the
world, far-less-expensive boulder opal came on strong in
America as a substitute. Then, during the withering of
world recession of the early nineties, when the Japanese also balked at
the high cost of black opal,
variety came on even stronger in Japan." (Source:
Australian Opals from Coober Pedys
Living underground in Coober Pedy..
See - http://en.wikipedia.org/wiki/Coober_Pedy
Australian Lightning Ridge Crystal
Mexican Fire Opals
with a base tone ranging from colourless to medium grey are called light opal. Some people
refer to these as "white" although this expression should only be used where the
body colour is very milky. Light opal makes up the bulk of precious opal. White Opal
may be transparent through to nearly opaque, although it usually has a "milky"
appearance and has a light body tone or white body colour. Mainly mined at Coober Pedy and
Mintabee, (South Australia) although the first deposits were found at White Cliffs (NSW).
" ( Source: http://www.codyopal.com/cody0405/aboutopals.htm
"The history of
Australian opals started as late as 1849 at a cattle station called Tarrawilla, near
Angaston some 80km outside Adelaide however, Australian opal did not appear on the world
market until the 1890s. Prior to the emergence of Australian opal on the market, opal was
sourced in Hungary and South America. Consequently, the Hungarian mines promoted the idea
that Australian opal was not genuine, probably because gems with such brilliant colour had
not been seen before. "
|So many patterns of color:
"Harlequins", "Flagstones", "Ribbons", "Peacpck
Tail", "Rolling Flash"
EBAY OPALS - 1/15/2010.