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Jade
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There are two types of jade; nephrite jade and jadeite jade. Nephrite jade has
been in use for centuries as material for carvings and other ornamental objects.
It has been revered by the Mayan culture of central and south America and by the
Chinese. All of the ancient artifacts of jade are of the nephrite variety. The
color is green with a secondary color of black which darkens and dulls the
overall color.
In the late 1700's, deposits of a new type of jade were discovered in Burma.
It has a much brighter green color without the secondary color mask and is also
found in a variety of colors; yellow, lavender, black, white, and orangey-brown.
This jade is called jadeite jade and is the more expensive of the two types.
Be aware that jadeite jade is commonly treated to alter its color. Deal only
with reputable jewelers who will guarantee that the jade jewelry you buy from
them is not treated.
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| Myanmar (Burma) (only source for jadeite), nephrite
sources; Guatemala, U.S., Canada, New Zealand, Australia, China |
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| Jadeite is found in the augite group (pyroxene
group) sodium aluminum silicate; Nephrite is in the actinolite group
(amphibole group) calcium magnesium iron silicate; monoclinic with
intergrown fine fibrous aggregate |
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| Opaque to translucent; R.I. 1.65-1.66 (jadeite);
1.60-1.62 (nephrite); Hardness 61/2-7 (jadeite); 6-61/2 (nephrite) |
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| Jadeite rare in fine colors; nephrite commonly
found worldwide; found in boulders so large ornamental objects possible |
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| Brown, black, violet, green, white, reddish,
yellow, gray |
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| Green, white and lavender colors commonly treated
by bleaching and then polymer impregnation; also dyeing to improve color
sometimes done; most jade is waxed to improve surface finish |
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| Avoid ultrasonic and chemicals; strong light can
bleach dyed colors over time |
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| Used as revered ornamental object by cultures for
over 6,000 years; Chinese believe that wearing jade brings good luck and
health |
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| Cabochons, bangles, beads, carvings, and discs |
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Nephrite beads $210 (for 10mm);
Jadeite beads $600 (for 10mm, commercial quality); Nephrite cabochons
$35/ea;
Jadeite cabochons & carvings based on color uniformity, translucency,
clarity, and brightness. In addition, premiums are added if patterns of
color are similar to Chinese characters symbolizing good luck and
health. |
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