Gem of the Month

Each month this section will feature either a topic of interest to gem lovers or one special gemstone with background on the material and its value.

Go to: Homepage -- what's new in faceted gems -- what's new in designer cabochons and gem carvings -- gem of the month -- gem of the month archive -- birthstone of the month -- key to all the codes used on the ACS site -- definitions of terms used on the ACS site -- how to order -- about ACS -- about the ACS cutters -- settings for these gems --faceting information -- purchase UltraTec equipment

 

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September, 2000

Citrine

Citrine, yellow to red-orange quartz, was once the Rodney Dangerfield of the gem world. Its sheer abundance being responsible for this "no respect" treatment. That has begun to turn around somewhat in the last couple of decades as fashions have repeatedly emphasized Earth tones and home shopping networks have marketed the various shades of citrine aggressively with catchy adjectives like "butterscotch" and "whiskey" . Actually, very little of the quartz which is mined is citrine. Natural stones tend to be pale yellow, often with smoky tones. The vast majority of citrine which is marketed is produced by heating smoky quartz (produces light to medium yellows) and amethyst (produces stronger yellows and orange-red to orangey brown shades). The treatment is usually done right at the mine, and is stable, and fully accepted within the gem trade. Recently colorless, rock crystal quartz from certain mines has been irradiated and heated to produce a neon, slightly greenish yellow, usually called Lemon Quartz. In the past, it was commonplace for citrine to be given misnomers such as, "Brazilian topaz", or "Madeira" topaz, etc. The higher gemological knowledge level of both jewelers and the public make this practice rare today. This gem is a fine jewelry stone, with no cleavage and a hardness of 7, furthermore, its availability in large sizes enables cutters to use it for dramatic and intricate custom cuts. It is also used for gem carvings. Stable in light and not very sensitive to chemicals, this stone requires no special care and can be used for any jewelry application. Virtually all citrine comes from Brazil.


Value

At the top end of the scale are prime specimens of the most saturated yellows, oranges and reddish tones. Those with less intense color fall into lower value ranges with pale or smokey stones at the bottom . As with any gem material custom cutting increases value and inclusions decrease it. There is no exponential increase in value per carat with increase in size as larger sizes are readily available. In many fancy cut or carved specimens the majority of the value is due to the artistry of the fashioning.


Gemological Data:

Makeup: silicon dioxide

Luster: vitreous

Hardness: 7

Crystal structure: trigonal

Cleavage: none

Density: 2.65

RI: 1.54

Birefringence: .009

Dispersion: .013


Stones Currently Available:

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Go to: Homepage -- what's new in faceted gems -- what's new in designer cabochons and gem carvings -- gem of the month -- gem of the month archive -- birthstone of the month -- key to all the codes used on the ACS site -- definitions of terms used on the ACS site -- how to order -- about ACS -- about the ACS cutters -- settings for these gems --faceting information -- purchase UltraTec equipment