Question

Name the following minerals: (a) \(\mathrm{MgCO}_{3},\) (b) \(\mathrm{Na}_{3} \mathrm{AlF}_{6}\), (c) \(\mathrm{Al}_{2} \mathrm{O}_{3}\) (e) \(\mathrm{HgS},\) (f) \(\mathrm{ZnS},(\mathrm{g}) \mathrm{SrSO}_{4},\) \({ }_{3},\) (d) \(\mathrm{Ag}_{2} \mathrm{~S}\) (h) \(\mathrm{PbCO}_{3}\) (i) \(\mathrm{MnO}_{2},(\mathrm{j}) \mathrm{TiO}_{2}\)

Short answer

(a) Magnesite, (b) Cryolite, (c) Corundum, (d) Acanthite, (e) Cinnabar, (f) Sphalerite, (g) Celestite, (h) Cerussite, (i) Pyrolusite, (j) Rutile.

Step-by-step solution

Identify Mineral (a)

The formula \(\mathrm{MgCO}_{3}\) refers to the mineral Magnesite. This is a carbonate mineral, composed mainly of magnesium carbonate.

Identify Mineral (b)

The formula \(\mathrm{Na}_{3}\mathrm{AlF}_{6}\) refers to the mineral Cryolite. It is an uncommon mineral of sodium, aluminum, and fluoride.

Identify Mineral (c)

The formula \(\mathrm{Al}_{2} \mathrm{O}_{3}\) is known as Corundum. This mineral consists of aluminum oxide and includes varieties such as sapphire and ruby.

Identify Mineral (d)

The formula \(\mathrm{Ag}_{2} \mathrm{~S}\) represents the mineral Acanthite, which is a prevalent ore of silver.

Identify Mineral (e)

The formula \(\mathrm{HgS}\) is known as Cinnabar. This mineral is recognized as the most common source of mercury.

Identify Mineral (f)

The formula \(\mathrm{ZnS}\) is known as Sphalerite. It is the main ore of zinc and is also termed zinc blende.

Identify Mineral (g)

The formula \(\mathrm{SrSO}_{4}\) translates to Celestite. This mineral is a sulfate consisting mainly of strontium sulfate.

Identify Mineral (h)

The formula \(\mathrm{PbCO}_{3}\) corresponds to the mineral Cerussite. This is a lead carbonate mineral, important as a lead ore.

Identify Mineral (i)

The formula \(\mathrm{MnO}_{2}\) is known as Pyrolusite. It is a common and important manganese mineral.

Identify Mineral (j)

The formula \(\mathrm{TiO}_{2}\) refers to the mineral Rutile, which is a major ore of titanium.

Key concepts

Carbonate Minerals

Carbonate minerals are a group of minerals that contain the carbonate ion, \( \mathrm{CO}_3^{2-} \), as their primary component. Many of these minerals play a crucial role in Earth's geology and the global carbon cycle. They are most commonly found in sedimentary rock formations and are also present in metamorphic and igneous rocks. Some well-known carbonate minerals include:

• Calcite (\( \mathrm{CaCO}_3 \)): This is the most common carbonate mineral, often found in limestone and marble.
• Magnesite (\( \mathrm{MgCO}_3 \)): Identified in the exercise, this mineral is important for producing magnesium-related products.
• Cerussite (\( \mathrm{PbCO}_3 \)): Also named in the exercise, it is a lead-containing carbonate mineral used as an ore of lead.

These minerals form through biological and non-biological processes, often from the accumulation of biological debris. Their solubility plays a part in controlling the chemistry of ocean water, affecting marine life and geological formations over time.

Sulfate Minerals

Sulfate minerals consist of minerals that have the sulfate anion \( \mathrm{SO}_4^{2-} \) in their structure. They can be found in a wide range of environments, from evaporation lakes to volcanic deposits. One major characteristic of these minerals is their solubility in water, sometimes forming through evaporation processes. Key sulfate minerals include:

• Celestite (\( \mathrm{SrSO}_4 \)): Mentioned in the exercise, this mineral is rich in strontium and is found in sedimentary rocks.
• Gypsum (\( \mathrm{CaSO}_4 \cdot 2 \mathrm{H}_2\mathrm{O} \)): Commonly found in evaporite deposits, gypsum is widely used in building materials like plasterboard.

These minerals can form spectacular crystal shapes and are an indicator of dry, arid conditions in geology. Sulfate minerals can also impact water quality and are used in various industrial applications, including fertilizers and detergents.

Oxide Minerals

Oxide minerals are composed primarily of oxygen and one or more metal elements. They are vital to various industrial processes and are prevalent as ores for metals. These minerals form under a variety of geological conditions, from igneous processes to sedimentary environments. Notable oxide minerals include:

• Corundum (\( \mathrm{Al}_2\mathrm{O}_3 \)): This mineral is graded as sapphire or ruby when colored and is known for its hardness second only to diamond.
• Hematite (\( \mathrm{Fe}_2\mathrm{O}_3 \)): An important iron ore valuable for its use in steel production.
• Rutile (\( \mathrm{TiO}_2 \)): As mentioned in the exercise, rutile is a major titanium ore and commonly found in igneous and metamorphic rocks.

Due to their diverse formation environments, oxide minerals are significant in determining the availability of metals and are extensively mined across the globe.

Silicate Minerals

Silicate minerals are the most abundant group of minerals on Earth's crust, primarily made up of silicon and oxygen with additional elements such as aluminum, magnesium, and iron. Their structure is based on the silicate anion \( \mathrm{SiO}_4^{4-} \) arranged in various configurations including rings, chains, sheets, and three-dimensional frameworks. Common examples include:

• Quartz (\( \mathrm{SiO}_2 \)): Known for its widespread presence and use in glassmaking and electronics.
• Olivine (\( \mathrm{(Mg,Fe)_2SiO_4} \)): Found in igneous rocks, this mineral is green and used as a gemstone.
• Mica group minerals: Characterized by layered structures, used in electronics for insulation purposes.

Because of their structural diversity, silicate minerals exhibit a wide range of physical properties and are integral to Earth's rock cycle. They offer insights into geological processes and are crucial for many industrial and technological applications.