Question

Which of the following minerals is primarily used for making ornaments and consists of Magnesium, Iron, and Silica?

• A. Amphibole
• B. Olivine
• C. Mica
• D. Pyroxene

Answer 1

Answer:

B. Olivine

Olivine: A Gemstone and Industrial Mineral

Composition and Properties:

• Olivine is a silicate mineral with the general formula (Mg, Fe)₂SiO₄.

• It is a solid solution series between the end-members fayalite (Fe₂SiO₄) and forsterite (Mg₂SiO₄). This means it contains varying proportions of Magnesium, Iron, and Silica.

• The color of olivine typically ranges from yellow-green to olive-green, which gives it its name.

• It is known for its vitreous luster and transparent to translucent appearance when found in gem quality.

Use in Ornaments:

• Gem-quality olivine is known as peridot.

• Peridot is a popular gemstone used in the creation of jewelry, including rings, necklaces, and earrings.

• It is one of the few gemstones that occur in only one color: green.

• Historically, peridot has been associated with various symbolic meanings, including protection and good health.

Industrial Applications:

• Beyond its use as a gemstone, olivine is also an important industrial mineral.

• It is extensively used as a refractory material due to its high melting point.

• Olivine sand is utilized in foundries for casting metals.

• It finds application in the production of slag cement and as a fluxing agent in steelmaking.

• Furthermore, olivine is being explored as a material for carbon capture technologies and for stabilizing atmospheric CO₂.

Occurrence:

• Olivine is a common mineral in the Earth's upper mantle and is found in mafic and ultramafic igneous rocks.

• Significant deposits are found in various locations worldwide, including the United States (Arizona, Hawaii), Myanmar, Pakistan, and Norway.