AMERICAN MUSEUM GUIDE LEAFLETS 
In order to understand better the chemical system used as a basis 
for classifying minerals, it is more convenient to group these 20 common 
elements into two classes, metals and non-metals. 
Metals. Aluminum, Iron, Calcium, Potassium, Sodium, Mag- 
nesium, Titanium, Barium, Manganese, Strontium, Zirconium, and 
Nickel. 
Non-metals. Oxygen, Silicon, Hydrogen, Carbon, Phosphorus, 
Sulphur, Chlorine and Fluorine. 
It is this last series of the non-metals which is especially important 
to remember, because in the combinations of one or more non-metals 
with one or more metals which, in general, go to form minerals it is the 
non-metals which determine in what class the mineral is to be placed. 
So we have for some of the principal divisions of the classification of 
minerals: 
Sulphides, composed of sulphur and some one or more of the 
metals, as sulphide of copper, the mineral Chalcocite. 
Chlorides, composed of chlorine and a metal, as chloride of sodium, 
the mineral Halite. 
Oxides, composed of oxygen combined with some of the metals, as 
oxide of iron, Hematite. 
The oxides of the metals, which have different properties from the 
uncombined metals, sometimes combine with the oxides of the non- 
metals and form more complex compounds which are called oxygen 
salts and constitute important divisions of the mineral classification. 
Some of these are the Carbonates, the Silicates, the Phosphates, the 
Sulphates, ete. 
NAMES OF MINERALS 
It is a general rule in the natural sciences, such as Botany and 
Zoology, to preserve in the name of a plant or animal either some word 
of Latin or Greek origin (because these are at present the universal 
languages of science) which describes a characteristic of the species, or 
to perpetuate in naming it the surname of some distinguished man con- 
nected with its discovery. This very general rule has been applied to 
the naming of minerals and the termination 7zte or lite! is almost always 
added. For example, Hematite is named from the Greek word for blood 
because its common varieties are red in color; Haiiynite is named after 
1Originally from Aidos, a stone. 

