One question we hear frequently from prospective buyers is, "What are the best values in natural gemstones in today's market?". We've been giving the matter some consideration so here are our thoughts on the topic.

Prices on gemstones go up and down depending on supply and demand, but generally they go up over time, sometimes dramatically. According to one service that has been tracking gemstone prices over the last 3 years, prices have risen an average of 20% since mid-2005. Those that have risen the fastest (around 30%) include tanzanite and Burmese ruby. Smaller increases (around 15%) have been seen in tsavorite garnet, tourmaline and zircon. Blue sapphire, spessartite garnet, spinel and peridot have seen increases around the average of 20%.

Based on that information, virtually every gemstone variety is a good value today, since they are all likely to be more expensive next year. But the buyer asking the question has, it seems, something else in mind. He wants to know, as the Americans say, how do you get "the most bang for the buck."

Since beauty is to some considerable degree in the eye of the beholder, we wouldn't presume to tell you what the most beautiful gemstone is for your money. But we can tell you which stones have the best gemstone characteristics based on their per carat price. And that seems to us to be a reasonable way of defining gemstone value.

Good gemstone characteristics, in our view, include superior hardness (greater than 7 on the Mohs scale), durability (absence of cleavage), very good transparency and clarity, and interesting colors. Absence of any sort of gem treatment would be would be a definite plus as well.

Since there are not that many gem varieties with a hardness greater than 7, it didn't take us too long to put together a short list of the best gemstone values. We didn't try to rank them, or say which is "best"; we think the short list is information enough for prospective buyers who want to make sure they are considering the right options in the market. Here is our short list:

Sapphire

Pros: hardness of 9; no cleavage; high refractive index (so excellent brilliance); good dispersion (fire); good choice of colors though blue is the perennial favorite.
Cons: usually heat treated
Price range: $300-$600+ per carat for heated sapphire; $1000+ per carat for unheated sapphire

Spessartite Garnet

Pros: hardness of 7.5; indistinct cleavage; very high refractive index (higher even than sapphire); always untreated
Cons: available only in yellow-orange to orange-red
Price range: $75-$150+ per carat

Spinel

Pros: hardness of 8; indistinct cleavage; high refractive index; very good fire; wide choice of colors; always untreated
Cons: can be difficult to find, especially in larger sizes
Price range: $50-$400+ per carat, depending on size

Tourmaline

Pros: hardness of 7 to 7.5; indistinct cleavage; good brilliance and fire; amazing choice of colors; affordable in large sizes; usually untreated
Cons: stones tend to be highly pleochroic or multicolored
Price range: $25-$150+ per carat, depending on size; paraiba tourmaline $300 to $1000+ per carat

Notes:

Price ranges are approximate, based on our current inventory. Upper limits for any gemstone variety are always unlimited, since very special pieces are priced accordingly.

There are many fine gemstones which didn't make our short list, including ruby, zircon, topaz, emerald and tanzanite. Our intention is not to disparage any of these, but to identify the very best values in today's market, based on the gemstone characteristics cited above.