Why is oxide mineral group important

Gem varieties of Corundum and Spinel, along with Chrysoberyl, can potentially lose their quality of color with prolonged exposure to light. Thus, enthusiasts and collectors should perform due diligence to determine the sensitivities of their prized specimens, and do their best to avoid exposure to conditions which might adversely affect their value.

Overall, oxide minerals are an intriguing and varied lot — with much to offer the rockhound or collector. To learn more about adding variety and interest to your rock and mineral collection, feel free to explore the Wisdom Pocket's other informative articles — or browse our current collection of rare oxide minerals , including this unique collection of sparkling Cuprites from the Milpillas locale.

They won't last long! Discover Oxide Minerals Mar 13, This significant copper over 26 pounds! Espirito Santo in Southeast Brazil is home to some of the world's most classic chrysoberyls. Sulphide minerals tend to have a metallic sheen. Many sulphate minerals form when sulphate-bearing water evaporates. A deposit of sulphate minerals may indicate that a lake or sea has dried up at that location. Sulphates with calcium include anhydrite, and gypsum Figure 5. Sulphates with barium and strontium are barite and celestite, respectively.

The anions in halides are the halogen elements including chlorine, fluorine, and bromine. Examples of halide minerals are cryolite, fluorite, and halite Figure 5. Halide minerals are made of ionic bonds. Like the sulphates, some halides also form when mineral-rich water evaporates.

The copper minerals malachite and azurite are also carbonates. The carbonate mineral calcite is the main component of rocks formed in ancient seas by organisms such as corals and algae. The apatite group of phosphate minerals Figure 5. Turquoise is also a phosphate mineral Figure 5.

We group minerals into classes on the basis of their predominant anion or anion group. These include oxides, sulphides, carbonates, silicates, and others. Silicates are by far the predominant group in terms of their abundance within the crust and mantle. They will be discussed in Section 2. Some examples of minerals from the different mineral groups are given in Table 2. Oxide minerals have oxygen O 2— as their anion, but they exclude those with oxygen complexes such as carbonate CO 3 2— , sulphate SO 4 2— , and silicate SiO 4 4—.

The most important oxides are the iron oxides hematite and magnetite Fe 2 O 3 and Fe 3 O 4 , respectively. Both of these are important ores of iron. Corundum Al 2 O 3 is an abrasive, but can also be a gemstone in its ruby and sapphire varieties.

If the oxygen is also combined with hydrogen to form the hydroxyl anion OH — the mineral is known as a hydroxide.