Minerals

A mineral, by definition, is unique from its synthetic analogues created in the laboratory. Artificial minerals, such as emeralds, sapphires, diamonds, and other expensive gemstones, are made on a regular basis in industrial and research facilities and are frequently nearly identical to their natural counterparts.

Nomenclature of Minerals

While minerals are divided logically into groupings such as oxides, silicates, and nitrates based on their principal anionic (negatively charged) chemical constituents, they are named in a considerably less scientific or uniform manner. Names may be given to reflect a physical or chemical quality, such as colour, or they may be drawn from a variety of things thought acceptable, such as a location, public figure, or mineralogist. The following are some examples of mineral names and their derivations: Albite (NaAlSi3O8) is named after the Latin word for “white” (albus); goethite (FeO.OH) is named after the German poet Johann Wolfgang von Goethe; manganite (MnO.OH) is named after the mineral’s composition; franklinite (ZnFe2O4) is named after Franklin, New Jersey, United States, where it occurs as the dominant ore mineral for zinc (Zn); and silliman Since 1960, the International Mineralogical Association’s Commission on New Minerals and Mineral Names has studied descriptions of new minerals and requests for new mineral names, attempting to eliminate discrepancies. This committee must accept any new mineral name, and the type sample is typically preserved in a museum or university collection.

Occurrence and Formation

Depending on where they are in the earth, minerals can be made in a wide range of conditions, such as temperature and pressure. There are four main types of mineral formation: (1) igneous: minerals form from a melt, (2) sedimentary: minerals are formed when other rocks that have been weathered and eroded are deposited together, (3) metamorphic: new minerals form at the expense of older ones because of changes in temperature or pressure on some existing rock types. The first three processes usually lead to types of rocks that have different mineral grains close together in an interlocking fabric. (4) Hydrothermal solutions, as well as solutions at very low temperatures (like groundwater), tend to follow fracture lines in rocks. These fracture lines may be places where minerals can be chemically precipitated from solution. It is from these open spaces, which have been partly filled with minerals from solutions, that most of the most beautiful mineral specimens have been found. if a mineral that is in the process of growing (like when it is precipitated) is allowed to grow in a free space, it will usually have a well-developed crystal form, which makes a specimen more beautiful to look at Similarly, geodes, which are round, hollow, or partially hollow bodies that are found in limestones, may have well-formed crystals that line the inside of the cavity. Geodes are formed when minerals, like those found in groundwater, are deposited.

Properties Of Minerals

The most common minerals in the Earth’s crust can often be identified in the field by their colour, shape, and hardness. It’s also important to think about the mineral’s surroundings. Some minerals can form under the same conditions, so you’re more likely to find them in the same rock. Other minerals, on the other hand, form under very different conditions and won’t be found in the same rock. For this reason, context can often be used to rule out minerals that have the same colour, for example. The other minerals and type of rock in the area can help. There are a lot of minerals that have been named, but only a few are found in the Earth’s crust.

Crystal Form

The outside shape of a mineral crystal (or its crystal form) is mostly determined by its internal atomic structure, which means this property can be very useful. When we learned about Steno’s Law of Interfacial Angles in Minerals Module I, we learned that the shape of a crystal is determined by the angle relationships between its faces. A cubic shape is found in some minerals, like halite (NaCl, or salt) and pyrite (FeS). A prismatic shape is found in other minerals, like tourmaline. This means that some minerals, like copper ores azurite and malachite, don’t have crystals. They are amorphous.

We don’t always get to see the crystal form. Crystals that are perfectly formed only show up in places where they have had time to grow into, like in a geode. However, when crystals grow in the context of magma that is cooling, they have to compete for space with all of the other crystals that are also trying to grow. They fill in as much space as they can. There is a lot of room for the shape of the crystal to change based on how much space there is. The angle of each crystal face will always be the same, though.

Conclusion

Minerals are classified based on their chemical composition, which is shown in their physical traits. This is the second module in a series about minerals. It talks about the physical properties that are used to identify minerals. These include the colour, crystal shape, hardness, density, lustre, and cleavage of each piece.