4
CONTENTS.
XVIII. Quartz Family—Rock-Crystal, Amethyst, Agate, Onyx,
Sardonyx, Nicolo, Chalcedony, Sapphirine, Carnelian,
Sard, Chrysoprase, Plasma, Cat's-eye, Heliotrope (or
Bloodstone), Cairngorm, Aventurine, Jasper, Prase, Iris,
Novaculite, Arizona Petrifactions.........349
Appendix A. Size of Large and Remarkable Diamonds.....371
Appendix B. Classification of Precious Stones, according to
their Principal Constituents.........374
Appendix C. Hardness and Specific Gravity of Precious Stones . 377
Appendix D. Relative Hardness of Precious Stones......379
Appendix E. Relative Specific Gravity of Precious Stones . . . 380
Appendix F. Localities in the United States where Gem-Minerals HAVE BEEN FOUND............381
