Emerald

Accurately describing gem color is critical to determining a gemstone’s value. Learn how to grade hue, tone, and saturation and avoid some common…

Detailed information for any gemstone you are interested in.

The Mohs hardness scale measures a mineral’s resistance to scratching. Find the traditional scale here and a chart of select gems ordered by hardness.…

Can gem grading avoid subjective terms? Learn about gemologist Jeff Graham’s common sense gemstone grading system, an alternative to commercial…

Although long known best for being misidentified as ruby, the spinel gem is beautiful in its own right. Its colors, durability, and relative affordability…

Gemology is both art and science. Learn how identifying gemstones combines traditional testing techniques, modern software, and deductive…

Considering buying gems in Afghanistan? Learn which Afghan gemstones to seek out, which to avoid, and prepare for a “buyer beware” experience.…

Learn essential ruby buying tips from experts. Discover how to evaluate color, clarity, cut & carat weight. Avoid synthetic stones & treatments.…

Turkey’s gemstones include well-known species such as diaspore, chalcedony, and purple jade, as well as unusual specimens of lesser-known gems.…