CHRYSOLITHUS	93
	The Chrysolithus of Pliny (42), or at least his best sort, the Indian, was the gem now commonly but improperly styled the Oriental Topaz, a yellow variety of the Sap­phire, and of equal hardness and rarity. The ancients obtained it from Ethiopia (a vague term for the remote East), together with the Ilyacinthus (Sapphire) : a natural companionship, both being Corundum but differently coloured—the blue and yellow Jacut of the Persians. The description, " transparent, with golden lustre," applies to no other gem so exactly as to this. Such is its brilliancy that when Do Boot wrote it was considered superior to the White Sapphire for imitating the Diamond, after the colour had been extracted by heat. In the first class were placed the Indian, and those brought from Tibara, if not cloudy (turbidas). The test of their quality was that their intense yellow should make gold compared to it look as pale as silver itself. This golden lustre is a conspicuous quality in the Oriental Topaz, the Brazilian, on the contrary, being betrayed by a vinous tingo. The Arabian Chrysolithi were most pro­bably no other than the modern Jacinths, for Pliny's account of them applies exactly to the latter gem : " They are in least esteem of the whole class, being turbid and of different shades ; and even when limpid their lustre is