JADEITE - Canadian Institute of Gemmology

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through use of the refractometer. Unfortunately, the form of the objects or their use in jewelry often
precludes the use of a refractometer. Thus, it is often necessary to use other means of testing the
stones. The following is a list of the various simulants with a brief discussion of their
characteristics. The list has been derived from a variety of sources (e.g., Whitlock and Ehrmann
1949: 28-29; Read 1999: 222; Lyman 1986; Schumann 1997; Hall 1994; Hankin 1998; Koivula
1982; and Field 2000).
1) Agalmatolite. The greenish variety is often used to imitate jadeite. It is also called pagodite,
pyrophyllite, and "figure stone". Webster (1975: 232) notes that "the lower density, about 2.80,
confirmed by the low hardness of 2.5 on Moh's scale precludes any confusion with the jades." It is
found in Finland, Slovakia, South Africa, and the United States.
2) Alabaster. Alabaster is sometimes dyed to simulate lavender jadeite (see Field 2000: 3). Its
refractive index is 1.52-1.53.
3) Amazonite. Amazonite is an opaque sodium feldspar (KAlSi 3O 8) that is found in green and
blue-green colors. Its refractive index is 1.522-1.530 (some sources give it as 1.52-1.54), its
specific gravity is 2.56, and its hardness is 6. In addition to these distinguishing characteristics,
Amazonite also has a different look than jadeite (or nephrite). It is found in the United States
(Colorado, and hence sometimes called "Colorado Jade"), Brazil ("Amazon Jade"), India, Kenya,
Madagascar, Namibia, and Russia.
4) Astridite. I have been able to find relatively little information on this stone, but Webster
(1975: 232) lists it as a jade simulant. He describes it as "a chrome-rich precious stone said to be of
a dark green colour with lighter coloured veins and to be a chrome-rich jadeite intergrown with
picotite, quartz, opal and limonite, and to have been derived from an olivine rock." It has a density of
3.35. He states that it comes from "New Guinea", but does not elaborate as to whether this means
Papua New Guinea or Irian Jaya (Indonesia). I have tried to find more information on this stone,
but have found it mentioned in only one of the web-sites that I consulted. Mindat.org describes
astridite as "an ornamental stone, primarily chromian Jadeite," but adds that its IMA status is "not
approved", its locality is doubtful, and there are no references on the stone.
5) Aventurine. This variety of quartz (Hauff 1993: 86 describes it as quartz with fuchsite)
comes in light to dark green often with metallic iridescence that is known as aventurescence. Hobbs
(1982: 11) describes the fuchsite inclusions found in aventurine as densely packed round green
platlets ("disc-like"). It is sometimes referred to as "Regal jade" or Imperial yu". Its refractive index
is 1.544-1.553 (some sources give it as 1.54). Its specific gravity is 2.66 and its hardness 7.0.
Aventurine is sometimes dyed. Webster (1975: 232) notes that it "is so manifestly different in
appearance to the true jades that no confusion should arise." Aventurine is found in Mexico, Brazil,
India (hence, it is also sometimes referred to as "Indian Jade"), Austria, Russia, and Tanzania.