Quantcast
  We will be migrating to a new server in the next two weeks, and apologize for any temporary slow response Portal logo
Login/Register
 
/gemstones/goodchild-precious-stones/page_049 - 2
 

Ch. 3: Physical Properties of Gem Stones

Ch. 3: Physical Properties of Gem Stones Page of 311 Ch. 3: Physical Properties of Gem Stones Text size:minus plus Restore normal size   Mail page  Print this page
44
PRECIOUS STONES.
this accounts for much of the variation. For example, Quartz in its crystalline forms of Rock Crystal, Amethyst, etc., has the standard hardness of 7'0, but the cryptocry-stalline varieties Agate and Chalcedony have a hardness of only 6-5 in some cases.
VII. Cleavage.
Minerals which occur in crystalline masses or in actual crystals (vide infra) have a very definite internal arrange­ment of the molecules composing them, causing the mineral to have different properties in different directions, whereas
Ch. 3: Physical Properties of Gem Stones Page of 311 Ch. 3: Physical Properties of Gem Stones
Suggested Illustrations
Other Chapters you may find useful
Other Books on this topic
bullet Tag
This Page