Thursday, December 11, 2008

Opal Fire Patterns

I wanted to continue our series on opals today. We've talked before about some of the general terminology of opals. In this article I wanted to try and define the terms used to describe a precious opal's fire pattern. Every opal is different but opal dealers have put them into categories to make descriptions easier. There are seven generally accepted categories used in the opal trade. The most common are "pinfire", "broadflash", "flashfire",and rolling broadflash. There is also what are referred to as harlequin. And others are categorized as rare patterns or picture stones.
Here is a description of each:
  • Pinfire opals have tinyl pinpoint circles of fire.
  • Flashfire has larger areas of fire that are irregular in shape. The splashes of fire can be fairly large but no one area would cover more than 50% of the surface of the opal.
  • Broad Flashfire displays sheets of color covering large sections or all of the stone's surface.
  • Rolling Flashfire has sheets of color which roll across the surface of the stone as it is moved in the light. These are highly sought after and almost impossible to accurately photograph.
  • Harlequin. A true harlequin opal has square or angular blocks of fire set closely together. They are extremely rare and very valuable. Patterns that are not regular are also especially valued but not true harlequins.
  • Picture Stones are opals that have an unusual pattern that resembles a picture of something, kind of like with picture jasper.
  • Rare patterns, as you might imagine, is kind of a catch-all category for everything else.
Opals can be very difficult to photograph and even harder to describe. Hopefully knowing these terms will make it a little bit easier to visualize what an opal looks like when you read a description and easier for you to describe one to someone else.

Monday, December 01, 2008

What is the December Birthstone?

That seems like a simple enough question. But the answer isn't that easy. It depends on who you ask (and maybe what they are selling!). Different cultures at different times have adopted different versions of what stones go with which month. In ancient India the December birthstone was Ruby. Among the Mystics of Tibet it was Onyx. In western societies the traditional December Stone was Turquoise or sometimes Lapis Lazuli. In more recent times it was declared by the Jewelers of America to be Blue Zircon. In 2002, the American Gem Trade Association added Tanzanite as a Birthstone for the last month of the year. Some listings also include Blue Topaz as an option. Discounting the ancient Indians and Tibetans, the common denominator is that it is something blue. If none of these work for you, there are also birthstones assigned for the zodiac symbols and for the days of the week!

The bottom line, to me, is that it doesn't matter. Some people feel obligated to wear stones or give somebody stones based on their birth month. Buy or give gemstones because you like the way they look or make you feel or because they go with what you are wearing. Don't worry about what
AGTA or your jeweler or some Tibetan Monk says you should wear.

Chart of the Traditional & Modern Birthstones