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cobalt spinel

Spinel is one of the birthstones for August. Among spinels, those that contain a large amount of cobalt and exhibit a bright blue color are called cobalt spinels. The shade of blue is thought to change depending on the cobalt content, and the darker the blue, the more valuable it is.

Karatz GemMagazine
" Cobalt Spinel "

KARATZ Custom Made

Why not take your favorite gemstone that you found at KARATZ and have it made into custom-made jewelry? It will be made by skilled Japanese craftsmen.
We carefully craft each piece of jewelry, starting with the stone setting, to match the individual characteristics of the gemstone.

The fifth reprint has been decided and is now on sale at bookstores nationwide and online.

Written by KARATZ, book “Jewelry Illustrated Book”

The book provides explanations about over 300 types of gemstones, from new standard birthstones to rare stones that are hard to find, as well as a diary of our company representative, Mr. Koyama's, gemstone shopping experience in Thailand and Sri Lanka, and tips for photographing gemstones, allowing you to learn about the appeal of gemstones from various perspectives.