Non-silicate minerals are minerals that do not contain silicon or oxygen as a tetrahedral structure. They have extremely different foundation and physical properties. They also have an unrestricted range of shapes, sizes and colors, and they are displayed by well-formed crystals.
The major basic group of non-silicate minerals is called native elements; these elements have a chemical formula that consists of only one element. This group of minerals includes gold, silver, copper and sulfur. Other non-silicate mineral groups, categorized according to their anionic chemistry, are the carbonates, halides, sulfates, sulfides and oxides. Each group has diverse chemistry and exhibits varying physical appearances.
Carbonates are known as rock-forming minerals, while the remaining groups are often ore minerals. Calcite and dolomite are two of the most important carbonates. Pyrite is the only sulfide that commonly occurs in rocks. Sulfides are significant economic minerals that provide the main source of elements such as zinc, mercury, nickel, lead, molybdenum, copper and arsenic.
Non-silicate minerals constitute less than 10 percent of the Earth’s crust. Carbon is found in diamond and graphite form. The carbonates, sulfides and oxides are the most common non-silicates. A few elements exist in pure form, such as gold, silver, lead, arsenic, copper, tellurium and bismuth. Many of the non-silicates are considered economically important, particularly those that include valuable metals. Some non-silicates are valued as gems due to their beauty, color and hardness.