FeatureGems & Gemology, Winter 1998, Vol. 34, No. 4

Characterizing Natural-Color Type IIB Blue Diamonds

John M. King, Thomas M. Moses, James E. Shigley, Christopher M. Welbourn, Simon C. Lawson, and Martin Cooper

Although rarely encountered, blue diamonds are among the most famous, and most distinctive, of fine gemstones. To better understand these unique gems, more than 400 were studied at the GIA Gem Trade Laboratory over several years to reveal additional information about the relationships between their color, clarity, and other gemological properties. The overwhelming majority of natural-color blue diamonds are type IIb. The color appearance varies widely from light to dark, but there is a limited range of color saturation. As a result, color appearance between neighboring GIA GTL color grades can be subtle. Of the blue diamonds examined at GIA GTL, few had any solid inclusions. Nevertheless, internal features such as graining and color zoning can make the processing of these diamonds a challenge.

こちらもご覧ください

YMAL GIA Ed
通学やオンラインでの教育について学ぶ
Learn About NextGem
GIA ネクストジェム(NextGem) ダイヤモンド研修 小売業向け
Explore GIA Laboratory Promotional Offers
GIAラボラトリーの特別オファーを見る
Shop the GIA Store
GIAストアで ショッピング
Characterizing Natural-Color Type IIB Blue Diamonds | Gems & Gemology