160                           PRECIOUS STONES.
	Among Granites, the Hyacinth (Jacinth ; or Zircon) occurs as a Gem, which is sometimes used e\ren in modern jewelry. It varies in colour from red to yellow, brown, green, grey, and white. In chemical composition it consists chiefly of Zircon (66 per cent), with silica (33 per cent), and a trace of iron-peroxide. When the Hyacinth is of a smoky-white colour it is called a Jargoon. In the eighteenth century this stone was supposed to be an inferior diamond. The word " Zircon " is from the Arabic, " Zerk." What medicinal properties Zircon can exercise—external, or internal— has not yet been ascertained. A doubt exists as to whether or not this stone was the true Zircon of the ancients. By some it is thought to be the Lyncurion of Theophrastus ; whilst the Hyacinth described by Pliny would appear to be the Amethyst, or the Sapphire, (having associated with it the blue " Fleur de Lys "). Anyhow, the Hyacinth was reputed in the Middle Ages to procure riches, honour, wisdom, and sleep. Furthermore, it would dispel evil spirits from the wearer. The roots of an allied Herb, likewise named " Jacinth," were used, 1696, " for the consolidation of green wounds." It was the " Hyacinthus vaccinium: or Lilium purpureum, "effectually helping the bloody flux and other Lasks." " Those persons," as M. Pomet directed, 1712, " who would have the Jacinth-stone for the confection that bears its name, must use no other than the milky Hyacinthus, being the true Oriental, and fit for medicinal use, it requiring no other preparation than to be ground toan impalpable powder." The Hyacinth (Jacinth) of the Garnet family " strengthens the heart; is specifick against the Crampe, and Convulsion ; it is counted, hung about the neck, for