An history of the wonderful things of nature set forth in ten severall classes wherein are contained I. The wonders of the heavens, II. Of the elements, III. Of meteors, IV. Of minerals, V. Of plants, VI. Of birds, VII. Of four-footed beasts, VIII. Of insects, and things wanting blood, IX. Of fishes, X. Of man
Jonstonus, Joannes, 1603-1675., Libavius, Andreas, d. 1616., Rowland, John, M.D.

CHAP. XXI. Of the Opalus, Emerald, Heliotrop, and Topaz.

OPalus is a Jewel, which when you hold it downward, it hath the clear fire of the Carbuncle, the shining purple of the Amethyst the green Sea of the Emrald, and all things else shining with an in∣credible mixture. An Emerald doth so change the ayr about it with its own tincture, that it will yield neither to candles, Sun light, nor shade. Hence in the water it seems greater. Those that are not perfectly green, of them, are made better by wine and oyl. They are seldom so great, as that you may grave a seal upon them. Yet there is one not very small at Lyons in a Monastery, and that which▪ was seen at Prague in the Chappel of St. Vencessius, it is above 9 parts of 12, greater than that, Bodin. l. 2. Theatr. There is one longer at Mag∣deburg, which is contained in part of the spire fashioned Cabinet, wherein the Host is carried; some say it was the handle of the knife of Otho the first. There was a Jewel once found in Cyprus, the one half of it was an Emerald, and half a Jaspir. The Emerald hath wonderful vertue; It is an Enemy to poysons and bitings of vene∣mous beasts; and it breaks, if they overcome it. It is said, to further womens labour, tyed to the hips; and to hinder it, laid to the belly, Sennert. l. 5. Epitom. Scient. natural. c. 5. Shut in a ring, or hanged about the neck, if it touch the naked flesh, it preserves from the Apo∣plex, Plat. l. 1. del f. It hath been known to break off from the fin∣gers of the Master of it that wore it, when he was dead. It cannot endure venery; for if it touch ones body in the act, it will break▪ Al∣bertus, the King of Hungary had one that brake at that time in 3. pieces. Heliotropium is a Jewel marked with bloody veins; cast into a vessel of water, it changeth the Sun beams falling on it, by reflexion, into blood colour. Out of the water it receives the Sun, like a burn∣ing Glasse, and you may perceive the Suns Eclipses by it, how the Page  112 Moon moves under. A Topaz is not onely transparent, but also shines wonderfully; and the brightnesse goes forth like gold: it is greater than other Jewels: for thence it was, that a Statue was made for Arsinoa Wife to Ptolomaeus, Philadelphus, of 4 cubits high, and was consecrated in the Temple that was call'd the golden Temple.