Posts Tagged ‘blue topaz’

December Birthstones : Tropical Blue Sea meets the Autumn Blue Sky

Turquoise had been popular in many ancient civilizations such as those in Egypt, Persia, China, and the Americas. Europeans got to know about this then “exotic gem from the east” from the Turkish traders (hence the name) that brought them over from Persia.
Turquoise art
Turquoise gems are still widely sought after today because of their unique combination of color and opacity. It is one of the most popular non-transparent gems around. Turquoise looks good on any setting, metal or otherwise. Cabochon, beads, and other fancy shapes are the most common cuts instead of facets. Exceptionally large nuggets and blocks of turquoise can also be sculptured into various types of wearable works of art or non-wearable decorative items.
Turquoise character
Turquoise has hues that vary from blue to green or yellow green, with all the possible combinations in between. It has a sheen or luster that is typically similar to that of wax or rough glass; and it is one of the softest of gemstones, having a Mohs scale hardness rating of only 6, which is one rank below that of the common mineral quartz. Turquoise specimens are also highly porous because they are made up of millions of individual interlocking cryptocrystalline turquoise crystals. Brown, black, or gray-brown flecks or veins made up of other minerals such as pyrite are often found embedded in turquoise.
Turquoise care
Because of its softness, turquoise is usually treated either with wax or resin. Wax treatment of turquoise has been practiced since ancient times and it does not add or detract from the value of the gem since most turquoise has a natural waxy luster. Bare turquoise pieces must be periodically waxed (with beeswax or paraffin) to protect them from light, heat, perfumes, moisture, sweat, and so on. Resin treatment imparts greater durability to each individual specimen compared to waxing. Resin treatments are sometimes preceded by color-enhancing treatments; but the highest quality turquoise gems do not need to be color enhanced and as such are only treated with colorless protective resins.
Blue Topaz
In contrast to the opaque turquoise, blue topaz–the substitute modern birthstone for December–is exceedingly clear and transparent, particularly the highest-quality gem specimens. Topaz typically has the luster of diamond or glass, which also contrasts with the waxy or rough glass luster of turquoise. Naturally blue topaz is quite rare and usually has a pale blue or sky-blue tone. The purer the blue hue (little or no extraneous browns or grays), the higher the values these gems acquire.
Topaz treatments
Some blue topazes get their color from radiation and heat treatments. These treatments are acceptable as long as they are declared. Usually the darker the resultant tone (e.g., London blue), the more expensive the specimen. However, note that irradiation and heat treatments may make topaz gems more brittle thereby making them more sensitive to mechanical stress and wear. Reputable labs that treat topazes indicate the appropriate enhancement codes and gem re-fashioning warnings on their product literature.
For additional information on topazes, please see our previous article on this November birthstone.

Tips on searching and getting the right quality stone

Buying a gem is a beginning of a life-long relationship and the price you pay is part of the deal. Understandably, you don’t want to pay too much..

So how can you tell if you are paying the right price?

First of all, don’t ask how much you should pay for a one-carat sapphire. A one carat precious stone can be worth few dollars or it can be worth up to $10.000. Quality makes the difference. Fortunately you can see differences in quality if you look at a lot of sapphire, ruby or emerald by looking side-by-side. Better color costs more, a lot more. Better clarity costs more. Better cut may cost a little more but it is worth it! The bigger the stone, the more it is per carat. Within each variety, prices are based on these four Cs, with color as the most important factor.

But different varieties have different price ranges. Some varieties are lower in price because they are readily available, some because the color isn’t very popular (brown and yellow stones, for example), some because the material is relatively soft, and some because …they have all the right stuff but no one knows it. There are plenty of examples of beautiful rare gemstones that cost less than gems that are less rare because they have a funny name, or people get them confused with an inexpensive variety or no one has ever heard of them. But enough about the injustice of the gem market.

We can break the price ranges of the different gem varieties down into five basic categories: traditional gemstones, new classics, connoisseur gems, collector gemstones, and affordable gems. These categories have basic price ranges, but, again lower quality stones or stones with less popular colors may cost less and stones with particularly fine quality or color may cost more. These price ranges are meant to give you a general idea of the relationship of prices between different kinds of gemstones and not to serve as a price list, since color and quality can make such a difference.

The traditional gemstones are ruby, emerald and blue sapphire. Because of their lasting appeal and distinguished history, ruby, emerald and sapphire are more valuable than other colored gemstones. Generally, ruby and emerald are also priced higher than a comparable quality sapphire due to rarity. For a one-carat stone of average to good quality in the varieties in this category, you can expect to pay between $250 and $10,000 per carat. Of course truly fine gems will cost more.

The new classics are gemstones that are the rising stars of gemstone jewelry: tanzanite, tourmaline, aquamarine,imperial topaz, and tsavorite garnet. These gemstones are sometimes available in standardized sizes but you really should look at some fine larger single stones to see why they have so many fans. Gems in this category range between $50 to $1,000 per carat for an average to good quality one carat stone, with a good example of tsavorite easily reaching $1500 per carat. depend on the size

Connoisseur gems are gemstones that have a more specialized market because they are more rare. These gemstones include black opal, jadeite, pink topaz, chrysoberyl cat’s-eye, fancy colored sapphires, and rare stones like demantoid garnet and alexandrite. These gemstones are highly prized and prices range from $250 to $1000 per carat, although alexandrite with a good color change will command at least $2000 even in a one-carat size.

Collector’s gems are not available in quantity to be marketed effectively so you get a lot of beauty for the money. This category includes spinel, zircon, moonstone, morganite and other beryls, and many rare gemstones. Red and hot pink spinels can command a few thousand per carat but most of the gems in this category will sell for hundreds not thousands.

Then there are the affordable gemstones, which combine great color with a surprisingly reasonable price and good availability. These gems include some old favorites and some new gems: amethyst, white opal, citrineperidot, rhodolite garnet, blue topaz, iolite, chrome diopside, kunzite, andalusite, and many ornamental gemstones such as lapis lazuli, turquoise, onyx, chrysoprase, nephrite jade, and amber. Prices for these gemstone range between $5 and $100 per carat for a one carat stone.

In every variety, especially the more expensive ones, you should expect to pay more for matched pairs, sets, and special shapes and cuts.