Hyacinth or jacinth, 136, 138. Hypersthene, 156.
I
Iceland spar, 39.
Idar-Oberstein, gem-cutting, 54, 55, 57, 143.
Idocrase, 160-161.
Igneous rocks, 6, 7.
Illam, 107, 109, 112, 113.
Imitation gems, 63-64.
Immersion method, 33, 34.
Imperial diamond, 100.
Indicolite, 135.
Indra Neela, 103.
Industrial diamonds, 49, 85.
Iolite, 158.
Iridium, 65.
Iron-tourmaline, 135.
J
Jacinth, 136, 138. Jade, 22. Jadeite, 146-152. Jaegar grade of
diamonds, 87. Jagdallak, Afghanistan, 107. Jaipur, 47, 78. Jargon, 138.
Jet, 165.
Jolly's balance, 27-29. Jonker diamond, 99. Jubilee diamond, 99-100. Judd, 136.
K Kaliguman, 125.
Kashmir
Sapphire, 103, 109, 110. Kimberley diamond mines, 9, 10, 75, 81, 82,
101. Kimberlite pipes, 72, 73. Koh-i-noor diamond, 74, 95. Konopi, 148.
Krauss and Slawson, 5. Kunzite, 61.
Kuruvinda—rubicelle, 104. Kyanite, 8, 21.
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