Diamonds And Precious Stones; Their History, Value, And Distinguishing Characteristics

Paperback | May 13, 2012

byHarry Emanuel

not yet rated|write a review
This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1867 Excerpt: ...as he supposes it to be the matrix or palace wherein the true ruby is found. The natives of India call the spinel Lai Rumani, or the pomegranate ruby, and ascribe to it valuable medicinal properties. The spinels and balas rubies, which are identically the same gems--the term spinel being applied to those of deeper hue--are frequently sold in error or by fraud for the true ruby; on the other hand, instances have occurred where a true ruby of pale colour has been sold for a spinel or balas ruby. To any one acquainted with the characteristics of these jewels, the mistake is impossible; the hardness of the ruby is far greater, and its specific gravity considerably more, and nothing can be easier than to verify these facts. An unset stone can be tested by taking its specific gravity; or if set, by attempting to scratch a sapphire with it; or by observing the refraction, which also differs, as a glance at Table A will at once show. The spinel is also occasionally mistaken for the garnet, on account of the similarity of colour in some of the specimens; still more frequently for the jacinth, from a like reason. Both these gems, however, are of inferior hardness; besides which, the jacinth possesses a strong double refractive power, whilst that of the spinel is single. The brown topaz, which is somewhat similar, may readily be distinguished by its property of acquiring electricity when heated. During the Middle Ages, the same supernatural powers were attributed to this stone as to the true ruby. Elianus, an ancient author who wrote a natural history of animals, relates that a stork once presented a woman, named Heraclis, with one of these stones, in gratitude for her kindness to it in curing a fractured leg. The spinel is cut on an iron wheel, with emery or diamond ...

Pricing and Purchase Info

$27.95

Out of stock online

From the Publisher

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1867 Excerpt: ...as he supposes it to be the matrix or palace wherein the true ruby is found. The natives of India call the spinel Lai Rumani, or...

Format:PaperbackDimensions:58 pages, 9.69 × 7.44 × 0.12 inPublished:May 13, 2012Publisher:General Books LLCLanguage:English

The following ISBNs are associated with this title:

ISBN - 10:0217826776

ISBN - 13:9780217826778

Look for similar items by category:

Customer Reviews of Diamonds And Precious Stones; Their History, Value, And Distinguishing Characteristics

Reviews