Last week we had a happy chat about topaz, the November birthstone. Lucky you. But luckily, we can all enjoy the beautiful variety of topaz to be found in antique jewelry. This week, we will touch on topaz colors.
Antique Victorian jewelry set #5132.
What an array of colors! Really?... Pure topaz has no color and is transparent. Impurities in the crystal tint it to
a wide range of shades. Colorless topaz may be foiled to give the impression of a more desirable color.
Natural pink topaz is very rare and costly;
#6306 pink topaz jewelry set.
Imperial topaz (yellow/orange-brown) is considered the most desirable and valuable of topaz tones and it commands commensurate prices;
#7412 Georgian Imperial topaz ring 
Orange is called Precious Topaz,
#5595 Georgian Iberian ring
Blues are regarded as less precious, albeit natural blues are rare. It can also be found in antique Georgian jewelry, in which case it is most likely natural.
#7093 blue topaz earrings. 
Smoky topaz is real topaz, but considered somewhat inferior to other forms of topaz. Nevertheless, it is a popular gem used in jewelry and it's relatively low value enables even those with small budgets to buy impressive pieces.
#5212 Great Arts and Crafts ring with smoky topaz.
Sherry topaz - a lighter variety of Smoky topaz.
Today, much topaz is heat treated for color. (see below) and some topaz is radiated to give a blue color.
Forewarned is forearmed: blue topaz is often the result of radiation and it only became
available in the 20th century. When you see blue stones with pink topaz in Georgian jewelry, they are usually aquamarines.
However, blue spinels have also been confused with topaz.
#6495 necklace with pink topaz and aquamarine. Was this believed to be blue topaz? 
Questions and comments: Please email antiques@brendaginsberg.com
Find jewelry on www.brendaginsberg.com