Читать книгу The Rare Earths: Their Occurrence, Chemistry, and Technology - Stanley Isaac Levy - Страница 8

The following list contains all but a few entirely unimportant members of these classes of minerals. The names of those species selected for fuller treatment are printed in heavy type, whilst names of those not so selected, which for convenience are included under the generic term ‘Rare earth mineral,’ i.e. roughly all those containing Thorium, or elements of the Cerium and Yttrium groups, and the commoner Zirconium minerals, as distinguished from minerals containing Titanium, are printed in italics. (See footnote on p. 4.) Their properties are given in the following order:—

Chemical Composition and Rare Earth Content.

Crystallographic Data.

Physical Properties.

Locality, etc.

The following contractions are employed:

E	=	any element or elements of the cerium or yttrium groups.
Cer	=	oxides of the cerium metals.
Yttr	=	oxides of the yttrium metals.
G	=	Specific Gravity.
H	=	Hardness.