gemology Flashcards
Light to dark, slightly pinkish
orange, reddish orange, yellowish orange.
Malaya
Medium to dark reddish
orange, red through slightly purplish red,
colourless (rare).
pyrope
Light to dark purplish red
through reddish purple
rhodonite
yellowish orange to reddish
orange.
spessartine
blanket term essentially used
to describe two types of gem-quality
metamorphic rocks: jadeite jade and
nephrite jade.
Jade
piedra de hijada,
referring to the stones’ shape as they
were found, resembling kidneys
term in china for nephrite jade
yu
green colour sometimes referred to as
“Imperial jade,”
known in China as “fei cui”
considered a 12th wedding
anniversary gemstone.
Jade
white, green, yellow to reddish orange,
brown, grey, black, light purple.
. Treatment with acid
followed by polymer resin impregnation
is referred to a
“B jade”
The classic and most important source
of jadeite is
Myanmar (Burma)
an
amphibole aggregate rock essentially
composed by actinolite-tremolite
Nephrite Jade
The pure white varieties, known in the
trade as
“mutton fat jade”,
first discovered near
Pala, in California’s San Diego County, a variety of the mineral
spodumene, a source for lithium which
was often used for industrial purposes. Delicacy and subtlety of colour are this
gem’s most notable attributes, making
it an excellent choice for eveningwear,
Kunzite
chromiumbearing variety, called
hiddenite
referred to by them as
“heaven’s stone.” Pharaoh Cleopatra VII had
a particular affinity for it shadow makeup. Further, it was used as a
blue pigment (called ultramarine) for many
centuries. described as
sapphirus
Lapis lazuli
Localities Lapis lazuli
Afghanistan’s mountainous Northeastern area of Badakhshan, notably in
Sar-e-Sang, is the world’s most famous
locality
Because of a work of fiction by Sir Walter
Scott, “Anne of Geierstein” written in
1829, attributing “enchanted powers” unlucky gem
Opal
where the vast majority of the world’s
opal is mined, the gem
Australia
An opal seam in the
matrix host rock where it formed, namely
ironstone. These can be very thin but still
exhibit extraordinary play-of-colour.
Boulder opal
An absorbent variety
of opal that may have play-of-colour.
Some material may appear as common
opal when dry, but which develops
play-of-colour phenomena when
immersed in liquid.
Hydrophane
birthstones for the
month of October, 14th wedding
anniversary
Opal
A milky, green opal found in Tanzania is
called
prase opal
Because of its water content, opal
is sensitive to heat and temperature
changes. Opal may develop a network
of tiny fissures over time, or if subjected
to heat or pressure. These fissures are
referred to as
“crazing”
remains among the most
important biogenic gem products
in jewellery
Pearl
Another form
of hardened tree resin is called
immature, or pre-fossilized amber.
copal