A question we frequently hear from customers is, "How much is a good sapphire?" It's not an easy question to answer because there are many different grades and colors of sapphire. Prices depend on carat weight as well. Still, it's a question worth answering, so here is our best attempt to answer it, based on our experience in the market.
Let's start at the lower end of the market and work upwards. The most inexpensive sapphires are carvings, since that's what the industry does with lower grade material that isn't suitable for gemstones. Carvings tend to be priced by the piece rather than the carat, since the work that goes into making them usually exceeds the cost of the material. You'll find small carvings starting at $10-20 per piece.
Next up in price are sapphire cabochons. Material of good color which is not sufficiently transparent to cut in facets is used to create the domed shape known as cabochon (or cab for short). You'll find these most often in blue and green, and they are often available in larger sizes as well, often up to 10 or 20 carats. The price per carat on the cabochons tends to be constant regardless of size, and we often have them at around $10 a carat. They can make some very attractive jewelry that has all the virtues of sapphire at a very affordable price.
You'll also find star sapphires in the cabochon-grade material. Here in Thailand we see several kinds of star sapphires. Our home province of Chanthaburi produces the untreated black and gold star sapphires found nowhere else in the world. We also have blue star sapphires that are diffusion treated with titanium to improve the star effect. Most of the star sapphires sell for around $10 a carat. Rare transparent star sapphires do exist but you'll find them mainly in museums.
Moving to faceted sapphire, the lower priced pieces will either be small sizes (under half a carat), heavily included material, or beryllium-treated. Prices for faceted sapphire start at about $20 a carat and rise according to size and color. In sizes greater than 1 carat you'll find clean beryllium-treated green sapphire at around $75 a carat, and yellow and red-orange pieces at around $100 to $120 a carat. We've noticed that the prices for beryllium-treated sapphire have been rising significantly in the last year.
Prices for heated blue sapphire depend very much on color and clarity. You can expect to pay around $300 a carat for clean pieces in the 1-2 carat size with good color saturation. Prices typically go up substantially for quality sapphire over 2 carats. We've had some excellent 2-2.5 carat blue sapphires at around $400 a carat and recently acquired a 5.09 carat Madagascar sapphire with IF clarity that is priced at around $600 a carat.
It is more difficult to state typical market prices for very fine unheated sapphire, since they are so rare. But we recently acquired two outstanding pieces from the Diego-Suarez mine in northern Madagascar. One piece is a stunning violet blue, 2.62 carats in weight and VVS clarity. It is a beautifully cut round, a shape that typically commands a premium in the market. We priced it at $965, which is probably unusually low for the market. A second unheated piece is a 6.33 carat rich blue with a hint of green, with a clarity grade of IF. It's priced at $5575. Generally you won't find fine unheated sapphire of any size at prices under $1000 a carat.