JADEITE - Canadian Institute of Gemmology

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used by ancient peoples" and cite the example of a "stunning necklace" with chrysoprase beads
found on an Egyptian mummy dating from around 1500 BC.
Crowhurst (2001: 113) states that "though lacking the toughness of jadeite, chrysoprase is
often harder, more translucent, and produces better polish and luster." The green color of the two
types of stone is somewhat different (the green of chrysoprase comes from nickel), especially in the
case of better quality jadeite. Its refractive index, which is given as either 1.530-1.540 or 1.55 in
various sources, makes chrysoprase easy to distinguish from jadeite. Its density is given as 2.6 and
3.48 in different sources. There were well known deposits in Silesia, but these were exhausted in
the nineteenth century. Today it is found in Australia (and is sometimes called "Australian jade" or
"Queensland jade"), Brazil, India, Kazakhstan, Madagascar, Russia, Zimbabwe, South Africa,
Tanzania, Mexico, and the United States (California). Garza-Valdés (1993: 111) notes that there
have been reports of Precolumbian artifacts from Guatemala being made of chrysoprase, but
comments that "I have been unable to document these findings" and "have not been able to discover
it in Mesoamerica."
9) Glass. There is a long history of using glass to imitate jadeite and such glass is sometimes
referred to as "Metajade" as well as "Imori" or "Iimori" after the Imori Laboratory in Japan.
Webster (1975: 233) writes that "a suitably coloured and opacified lead glass makes a convincing
imitation of jade." Goette (1976: 120, 122) discusses the use of glass as a simulant in China in the
1930s:
The Chinese glass worker has added his craft to the simulation of jade, generally of the
emerald green jadeite, or the mixed white and green nephrite known as American green.
While the disgruntled and disillusioned visitor might charge the merchant with cheating in
the sale of a string of glass beads, certainly the selling of such jewellery is not based on
dishonest imitation of jade. The Chinese admire their green glass, and they like to have it
approximate Fei Ts'ui in hue, form and appearance. Therefore, the glass maker has directed
his efforts to copying the emerald green of jadeite as closely as possible, since, as was said
before, the nearer to gem itself approaches flawless, translucent emerald green glass the
better it is in quality. it is a strange circle of circumstance, this meeting of glass and jade, and
it has intrigues the artisan to the point of producing examples which require careful
inspection to distinguish between the two.
The density of glass simulants (about 3.7) is generally higher than that of jadeite. Webster
(1975: 233) also notes that "the nature of the pieces is obvious when the surface is examined by a
lense for such a glass will show pit marks where included glass bubbles have been cut across."
Read (1999: 283) lists the refractive indexes of various types of glass as 1.50, 1.61, and 1.46.
Hobbs (1982: 11; also see Crowningshield 1973) discusses Metajade glass made by the Iimori
Laboratory in Japan and notes tht "this material can be detected by its inclusions as well as by its
other optical and physical properties." Under magnification, fernplike inclusions as well as gas
bubbles may be seen in metajade.