December has a total of four birthstones: blue topaz, turquoise, zircon, and tanzanite. Writing about all four stones in one post would create a novel! So, we’ve decided to make one post a week, so we can cover each of these interesting stones in more detail. So, for this week, we’ll focus on blue topaz.
The name topaz is believed to be named after the island Topazios (now Zabargad) which is an island in the Red Sea.
Topaz was thought to assure long life, beauty, and intelligence, as well as to give strength and break curses.
Blue topaz can be as large as 25 carats, usually. The largest faceted stone by weight ever recorded was a topaz, weighing over 22,000 carats.
Blue topaz has a hardness of 8 on the Mohs scale, but is considered to have poor toughness due to cleavage in the stone.
High heat can alter color, so it’s advised to remove the stone before using a jeweler’s torch.
Faceted topaz can hold such a high level of polish that it can be slippery to the touch. This can present some problems when attempting to set these stones in jewelry, which is why many jewelers use rubber-tipped tweezers to hold topazes.
Colorless topaz is irradiated and heated to produce the blue color that’s so well known. This is a very common treatment, with more than 90% of blue topazes going through some form of it.