Concerning Precious Stones And Jewels

In estimating the value of a gem, three principal qualities must be considered: color, brilliancy, and perfection. In the case of each gem there is a true color which is rare. Brilliancy depends upon certain structural qualities and correct cutting. Perfection is freedom from flaws or defects; but it is important to recognize that minor and especially invisible defects do not detract appreciably from the beauty of a stone which has the essential virtues of good color and brilliancy. To be sure, commercial value is directly influenced by the perfection of the stones, but stones may be genuine and of great artistic value and still contain very slight imperfections. Size and weight are less important characteristics bearing upon value. The purchaser who is unfamiliar with the technique by which value is determined must entrust the selection of gems to a jeweller of unquestioned integrity and unfailing accuracy of judgment. 

Strictly speaking the precious stones are only seven in number—the diamond, the pearl, the ruby, the sapphire, the emerald, the oriental catseye, and the alexandrite; but to these are often added the so-called semi-precious stones—such as the amethyst, the topaz, the tourmaline, the aquamarine, the chrysoprase, the peridot, the opal, the zircon, and the jade. 

The charm of precious stones lies mainly in their beauty—in brilliancy, clearness, and above all, richness of color—"the blazing red of the ruby, the angry green of the emerald, the cold blue of the sapphire, and the white hot glory of the diamond," so vividly described by Kipling in his story of the Naulahka. 

Two other qualities of precious stones, hardness and scarcity, add to their worth. To their hardness they owe their power of taking a high polish, as well as their durability; while their rarity, although a variable quality, is one of the chief elements of their value. 

Poets have always delighted in sentences studded with gems. We read in Proverbs, "A gift is as a precious stone in the eyes of him that hath it." Shakespeare's Juliet "hangs upon the cheek of night like a rich jewel in an Ethiope's ear." Milton, describing the approach of evening, says, "Now glowed the firmament with living sapphires." Browning's hillside at morning is "dew-pearled." 

And yet long association with pageantry and poetic imagination has not robbed jewels of their intimate personal character. A gem as a gift is the symbol of highest admiration. As a possession and ornament a jewel which combines the elements of beauty, genuineness, and appropriateness will be a continual satisfaction, a lasting source of pleasure.

A List of Precious and
Semi-Precious Stones and their
Characteristics 

Preceded by 

A Scale for Hardness 

The following list of stones comprises those generally used by jewellers. Their color, hardness, and sources of supply are stated. The scale for hardness which has been in use for a century or more, was devised by Professor Friedrich Mohs (1773–1839), a German mineralogist. 

Scale for Hardness

1. TALC—very soft 
2. GYPSUM—soft 
3. CALCITE—low degree of hardness 
4. FLUOR-SPAR—fairly hard 
5. APATITE—medium hardness 
6. FELDSPAR—scratches glass 
7. QUARTZ—quite hard 
8. PRECIOUS TOPAZ—very hard 
9. CORUNDUM—hardest mineral except diamond 
10. DIAMOND—hardest mineral