If you're new to buying gemstones, or just new to buying online, this guide will help you find the best gems to meet your needs. If you're already an experienced buyer, you may find some useful hints on how to use our website tools to quickly find the gems you need.
What do you need?
If you're buying a gemstone to be set in a piece of jewelry, you may need a stone in a "calibrated" size to fit a standard jewelry setting. Consult our calibrated size chart to find gems in in standard sizes. If you're having a piece custom-made, a good jeweler can create a setting for any size of stone, so you don't need to worry about calibrated sizes.
Do you have a favorite gemstone? A favorite color? A favorite shape? Are you searching for a birthstone or anniversary stone?
Click on the "details" button for any gem to see larger photos of that stone. All of our photos are photos are specific gemstones offered for sale, and we show each gem from 3 different angles. Please make note of the size of the piece you're looking at, since the gems are magnified to give you the best view of the stone's clarity, cut and color. Be aware that a 1 carat stone may look just as a big as a 10 carat piece in the photos!
If you are looking for a particular color, such as pink, but you're not sure what kind of stone you want, you can find all the different gemstones in pink by typing "pink" in the search box that you'll find on the right side of every page.
The same technique works for searching for all gemstones in a particular shape, such as "pear" or "octagon". Or you can make a combined search and look for all the "blue oval" gems.
To learn more about a particular kind of gemstone that interests you, please see our information pages. These pages provide detailed information on specific gems, including what to look for in that particular variety.
If you want to get very specific, you can use our 'shop by' menu to search by any combination of gem type, weight, size, clarity, shape or price.
Colored gemstones, like diamonds, are valued according to the "4 Cs" - color, clarity, cut and carat weight. But where the diamond industry has a well-defined grading scheme for diamonds, there is no single grading system for colored stones. That's not surprising really, since there are more than 50 varieties of colored gemstones, and each has different characteristics. The standards for clarity in an emerald, for example, are quite different than for a sapphire, because even the most expensive emeralds have some natural inclusions.
All gemologists would agree that in colored gemstones, color is the single most important characteristic. Gemologists try to be quite precise about color, and they use a specific terms for describing the color of gems; hue, saturation and tone. See our color page for detailed advice on evaluating gemstone color.
Cut and clarity are also very important, especially because they affect color and brilliance. Colored gemstones are typically graded according to a clarity scale, and every gem listed on GemSelect has a clarity rating. In general, a gem that has no visible inclusions is preferred. But it is important to note that inclusions often add character and individuality to a gem. In fact, gemologists use the distinctive character of inclusions to identify the origin of a stone. Indeed, some inclusions are desirable. While it is true that the higher the clarity grade, the higher the value of the gem, inclusions that don’t interfere with the brilliance and sparkle of a gem don’t affect its value.
Many gems today are treated or enhanced in various ways to improve color and (sometimes) clarity. It is important to understand why some gems are treated, and what the different methods are.
The supply of high quality gemstones is falling as mines are being depleted. At the same time, consumer interest in gemstones is increasing. These trends lead to a scarcity of fine gems, and a corresponding increase in prices.
The gemstone industry has responded to demand by developing certain treatments to maximize the color and clarity of the scarce yield from the remaining gem mines. The most common of these techniques is heat treatment, which improves gem color through the use of high temperatures, mimicking the effects of nature as gems are formed through heat and pressure. Other kinds of treatment include fracture filling, and the addition of certain chemicals such as beryllium to the heating process.
These treatments significantly improve the appearance of many gemstones, but they also affect the value of the stone. A treated stone is always less valuable than a similar untreated stone. But most stones that are routinely treated - such as ruby and sapphire - are now very rare in untreated form, which means that the untreated stones fetch a market price out of the reach of most consumers.
However, if you would prefer to buy an untreated stone, there are still many choices. A number of popular gems, such as tourmaline, spinel, amethyst and garnet are almost never treated.
Once you've invested in a fine gemstone, proper care will help keep it looking new and vibrant for many years. Most gemstones are very durable and require only occasional cleaning. But some gems require special care, since they are sensitive to temperature change, excessive light exposure or chemicals. Some gems, such as opal, have a significant water content, and should be protected from dry air.