John I. Koivula

The Gemological Properties of the Sumitomo Gem-Quality Synthetic Yellow Diamonds

James E. Shigley, Emmanuel Fritsch, Carol M. Stockton et al. · Gems & Gemology · 1986 · 47 citations · Full text

Natural Sciences, Materials Engineering, Materials Science +6

The Gemological Properties of Russian Gem-Quality Synthetic Yellow Diamonds

James E. Shigley, Emmanuel Fritsch, John I. Koivula et al. · Gems & Gemology · 1993 · 46 citations · Full text

Natural Sciences, Materials Engineering, Materials Science +10

The Gemological Properties of the De Beers Gem-Quality Synthetic Diamonds

James E. Shigley, Emmanuel Fritsch, Carol M. Stockton et al. · Gems & Gemology · 1987 · 44 citations · Full text

Natural Sciences, Materials Engineering, Materials Science +13

Emeralds from the Kafubu Area, Zambia

J. C. Hanco Zwaan, Antonín V. Seifert, S. Vrána et al. · Gems & Gemology · 2005 · 41 citations · Full text

Engineering, Mining Engineering, Metallurgy +5

Rubies and Fancy Sapphires from Vietnam

Robert E. Kane, Shane F. McClure, Robert C. Kammerling et al. · Gems & Gemology · 1991 · 28 citations · Full text

Natural Sciences, Earth Sciences, Geology +16