How to select quality gemstones and gemstone jewelry
Beauty. Rarity. Durability. Discover the attributes that attract us to colored gemstones for personal adornment and make gemstones valuable and precious. Colored gemstones provide the opportunity for uniquely personal expression. Use Jewelers of America’s guide to buying gemstone jewelry to ensure you select the highest quality gemstone jewelry for your budget.
How Gemstones Are Graded
While gemstones have similar quality factors as diamonds (cut, clarity, color and cut), they are valued differently for gemstones. For example, color is by far the most important C for colored gemstones, whereas cut is usually considered the most important C for diamonds.
Most colored gemstones derive their beauty from their color – purples, blues, greens, yellows, oranges, reds. Three factors relate to a gemstone’s color:
Hue: the pure color on the spectrum, describes the dominant color and any additional colors visible in a gem.
Tone: the lightness or darkness of a color. In the GIA color-grading system, tones range from very light to very dark.
Saturation or intensity: is the purity of the hue.
When buying colored gemstone jewelry, select what you consider beautiful. Because of the subtle differences in the tone and hue of the colored gemstone you are considering, look at several to find the one you prefer. Each gem variety has an optimal hue, tone and saturation, your jeweler can show you and explain the how gemstones each exhibit their optimal color.
Gem cutters work to achieve a pleasing and affordable mix of color, weight and a safe shape for mounting. During creation, a gemstone’s size is constrained by nature. For example, while large and beautiful amethysts are readily available, an alexandrite of large size is extremely rare.
Sparkle adds to the beauty of a well-cut colored gemstone. The cut of a colored gemstone describes its shape and how it is fashioned. Some gemstones, such as opal, are suited to a smooth, rounded surface. Others, such as sapphire, are more frequently shaped with a precise series of flat, symmetrical planes, called facets, which make the most pleasing illumination of the gem’s color. Some cutters today may also use convex or concave facets, shaping colored gemstone like small sculptures.
The clarity of colored gemstones contributes to their beauty. Unless a gemstone is opaque and blocks all light, how light moves through the gemstone affects its beauty. Some gemstones have few internal inclusions to interrupt the passage of light, as is the case with most pieces of tanzanite. Others have characteristic inclusions. For example, some emerald has a “jardine” (garden), which makes each gem truly unique.
Learn more about Clarity >