Sapphire Buying Guide

by International Gem Society

Mention sapphire and most people will probably imagine blue colored gems. Although blue sapphires are probably the most famous examples, these exquisite corundum gemstones come in virtually every color. Except red. (Red corundum is ruby). Long associated with royalty, sapphires are some of the most popular and expensive gems in the world. Their resistance to scratching makes them perfect for jewelry for every occasion. In rare cases, mineral crystal inclusions can create star sapphires, gems that display asterism or a stunning “star stone” effect.

“5.79 ct. Star Sapphire,” Thailand. © All That Glitters. Used with permission.

However, because gem-quality natural sapphires are rare and the demand so great, synthetics and imitations are common. Sapphire, like ruby, is also frequently subjected to treatments and enhancements. Before you embark on a sapphire buying adventure, learn how to evaluate a sapphire’s quality and avoid potential pitfalls.

Sapphire Buying And The 4 Cs

Color plays the greatest role in determining the value of a sapphire gem. Stones with vivid saturation will fetch the highest prices. Kashmir sapphires are the most highly prized. A sapphire from Kashmir will be valued higher than an equally graded stone from another source.

The International Gem Society (IGS) sapphire value listing has price guidelines for sapphires from various sources with different color and clarity grades, sizes, and cut styles.

For an excellent general guide to gemstone grading, see Donald Clark’s A Consumer’s Guide to Gemstone Grading.

Color

In the GIA color grading system, color consists of three qualities: hue, tone, and saturation. The basic hues are red, orange, yellow, green, blue, violet, and purple. Tone refers to a color’s relative lightness, from colorless (0) to black (10). Saturation refers to a color’s intensity, from grayish or brownish (1) to vivid (6). The dominant hue is capitalized. Other hues present are not capitalized and may be further described as “sl” for slightly and “st” for strongly.

Blue sapphires usually command the highest prices.

Top blue sapphire color consists of a hue of violet-blue or blue, a medium to deep tone of 5 to 6, and a vivid saturation, 6. These color grades are noted as vB 5/6, vB 6/6, B 5/6, and B 6/6. Only the corundum family of gems, rubies and sapphires, reaches vivid levels of saturation.

Very good blue sapphire colors range as follows:

Violet hue (V), tones and saturations of 4/6, 5/5, 5/6, 6/5, 6/6
Blueish violet hue (bV), tones and saturations of 5/6, 6/6, 6/7
Violet-blue hue (vB), tones and saturations of 5/5, 4/6, 6/5
Blue hue (B), tones and saturations of 4/6, 5/5, 6/5
Very slightly greenish blue hue (vslgB), tones and saturations of 4/6, 5/6, 6/6

Good blue sapphire colors range as follows:

Violet hue (V), tones and saturations of 4/5, 5/4, 5/5, 6/4, 6/5, 7/5
Blueish violet hue (bV), tones and saturations of 4/5, 4/6, 5/4, 5/5, 5/4, 4/5, 6/4, 6/5
Violet-blue hue (vB), tones and saturations of 3/5, 4/4, 6/3, 7/5, 5/4, 4/5
Blue hue (B), tones and saturations of 3/5, 4/4, 6/3, 7/5, 6/4, 5/4, 4/5
Very slightly greenish blue hue (vslgB), tones and saturations of 7/5, 5/4,6/4, 4/5, 6/5, 5/5
Greenish blue hue (gB), tones and saturations of 4/5, 5/5, 6/5

Sapphires with dark tones (7 and higher) are relatively more abundant than lighter stones and are not valued highly. Sapphires with light tones are referred to as “steely.”

After blue, pink is the most highly valued sapphire color. Padparadscha sapphires, pink-orange gems from Sri Lanka, are especially prized. For details on the color grading of pink, yellow, green, purple, and other sapphires, see our sapphire price listing.

“Pink Sapphire” by Amila Tennakoon is licensed under CC By 2.0

Clarity

Clarity refers to a gem’s transparency and anything that can impact how it transmits light. All corundum gems, including sapphire, are Type II gems in terms of clarity. That means sapphires usually contain inclusions. These are fractures and materials such as liquids, gases, and even crystals of other minerals inside their structure. For example, some sapphires can contain inclusions of crystal needles of the mineral rutile. The presence of rutile crystal inclusions may display a star effect.

Top tier values for sapphires of the same color grade go to stones that are clarity graded VVS (very very small inclusions), or what gemologists refer to as loupe clean. This means that even when examined with a 10x loupe, no inclusions can be detected. These gems are, of course, also eye clean. Loupe clean sapphires require microscopic examination in order to identify the nature and character of any inclusions. Since loupe clean sapphires are so rare, especially in larger sizes, a buyer should be extremely cautious and seek the counsel of a highly reputed laboratory to verify natural origin and lack of treatments before purchasing. In my experience, there are no “deals” to be had in fine sapphire – if it seems to good to be true, it almost certainly is. Finding a sapphire of this quality, in any size over one carat, irrespective of price, is a challenge.

The second tier of value for sapphires of the same color grade are stones that are clarity graded VS (very small inclusions) but still eye clean to SI (small inclusions), which may very well not be eye clean. In both instances, inclusions are numerous and/or large under a 10x loupe or are eye visible. The prominence of inclusions visible to the naked eye is the primary driver of value within this tier. If inclusions are prominently visible to the naked eye from any viewing distance, the value is impacted downward dramatically. Most commercially available “gem quality” sapphires fall somewhere within this second tier.

The third tier of value for sapphires of the same color grade are stones that are clarity graded SI to I (included), or clearly “not eye clean.” These eye visible inclusions may have a moderate effect on durability, and/or may be so prominent that the stone isn’t suitable for use in jewelry. These sapphires are plentiful.

Part of the appeal of Kashmir sapphires is their velvety appearance. This is caused by inclusions of very fine threads of rutile crystals known as silk.

Cut

Although cutting usually has the least impact of the 4 Cs on the value of colored gemstones, the quality and choice of cut does affect the value of a sapphire. Cuts that maximize light return, such as brilliant cuts, or those that enhance color, such as step cuts, are recommended. Emerald and marquis cuts add the most to a sapphire’s value, followed by round and pear cuts. Oval and cushion cuts are common for sapphires.

A cabochon cut can make a sapphire with the right arrangement of rutile crystal inclusions display a lovely asterism or “star stone” effect. Cabochons can also be used for sapphires with inclusions that would be considered too unsightly for faceting.

Carat

The price per carat of sapphires increases gradually at 2, 3, and 4 carat sizes. In comparison to their corundum brethren, rubies, high-quality smaller stones are not uncommon. Sapphires over 5 carats are rare and will see a jump in price per carat.

Sapphire Buying: Jewelry Considerations

A vivid blue sapphire makes a powerful statement, but there are enough color variations of sapphire to let you make an individual statement at many price levels. For example, a top color 1-carat blue kashmir sapphire may cost as much as $22,650. A top color 1-carat purple sapphire may cost as much as $570.

Sapphires come in every color. Except red. “Gemstone Hues,” by Donald Clark.

You can learn to live with sapphires that have eye visible inclusions. Eye visible means visible at a distance of approximately 6 inches. That’s very close. Clarity grades of VS to SI make a significant reduction in sapphire prices. A top color 1-carat blue kashmir with a clarity grade of SI to I may come down to $9,000. The same color grade stone with a VVS clarity score could cost up to $22,650.

A sapphire with a clarity grade of I or lower can still make a beautiful piece of jewelry. It just needs to be worn in an appropriate setting. A stone with inclusions that affect durability may not be a good choice for a ring or bracelet. However, it might do very well as a pendant or earring. (Please note, for any stone, a high hardness score doesn’t mean it’s indestructible. It only means it’s resistant to scratching).

Sapphire Buying Caveats

Sapphires have been created in laboratories for over a century. Modern techniques for synthesizing sapphires can create gemstones that are difficult even for experts to distinguish from natural. The presence of undisclosed synthetics in the marketplace is just one of the things the wary consumer needs to keep in mind.

Synthetic Sapphires

Synthetic sapphires are real sapphires. Chemically and physically they are indistinguishable from natural sapphires. This is no consolation, however, if you’ve unknowingly purchased a synthetic sapphire at natural sapphire prices. (In 2015, a customer filed a lawsuit against the jewelers who sold him a $9,000 pink sapphire in 1999 that turned out to be a $30 synthetic stone). Your best defense against purchasing an undisclosed synthetic is to have your new sapphire appraised by an independent gemology lab.

Colors And Origins

Sapphires are found all over the world, and the combinations of trace minerals found at their sources lead to subtle variations in color. Because of this, sapphire colors are sometimes referred to by country, “Burmese” or “Oriental” slightly violet-blue or “Thai” dark blue, for example. However, color alone is not enough to accurately identify the source of a sapphire. Nevertheless, sapphires are sometimes described as “African,” “Australian,” “Burmese,” “Kashmir,” etc. These trade names for sapphire colors misleadingly imply origins.

Less expensive gemstones are sometimes wrongly called “sapphires” in an attempt to make them more appealing to unwary consumers. For example, blue tourmaline is sometimes referred to as “Brazilian sapphire.” Due to sapphire’s strong association with the color blue, sometimes non-blue sapphires are deceptively renamed as varieties of gemstones with stronger associations with their color. For example, yellow sapphire is sometimes called “King’s topaz.” See our article on False and Misleading Gemstone Names for more information.

A “Ceylon Blue” sapphire from Montana. This gemstone listing makes a clear distinction between the color name and the origin of the stone. “Sapphire,” 1.04 cts., fancy round brilliant cut. © Dan Stairs Custom Gemstones. Used with permission. — A “Ceylon Blue” sapphire from Montana. This gemstone listing makes a clear distinction between the color name and the origin of the stone. “Sapphire,” 1.04 cts., fancy round brilliant cut. © Dan Stair Custom Gemstones. Used with permission.

Treatments And Enhancements

Heat treatments are applied to sapphires to remove rutile inclusions and improve color tone and saturation. Diffusion treatments, the application of a thin layer of color on the surface of a gem, are common for blue sapphires but rare for other other colored sapphires. Beryllium treatments have been used to turn light colored sapphires into padparadscha-like gems.

Heating is so common for both sapphires and rubies it doesn’t affect their value. Other treatments will affect value. For more information on these and other treatments applied to sapphires, see our article on Corundum Treatments.

Sapphire Buying As An Investment

If you think you’ve found sapphires at a bargain price and are considering making a purchase for investment purposes, read this article on investing in gemstones.