ANS:A - fluorapatite

Fluorapatite is a mineral that belongs to the apatite group, which is a class of phosphate minerals. It is a calcium phosphate mineral with the chemical formula Ca5(PO4)3F. In its pure form, fluorapatite is a transparent or translucent mineral that can range in color from colorless to shades of green, blue, or purple. Here's a breakdown of its composition:

• 𝐶𝑎5Ca5​: This indicates the presence of five calcium ions (Ca2+).
• (𝑃𝑂4)3(PO4​)3​: This represents three phosphate ions (PO43-).
• 𝐹F: This denotes the presence of fluorine atoms.

Fluorapatite is the most common phosphate mineral and is widely distributed in various geological settings. It is a major component of phosphate rock, which is mined for its phosphate content, primarily used in the production of fertilizers, such as single superphosphate and triple superphosphate. In addition to its importance in the fertilizer industry, fluorapatite also finds applications in various other fields, including the manufacture of ceramics, dental materials (as a component of tooth enamel), and in the production of phosphoric acid. Fluorapatite is distinguished from other apatite minerals by the presence of fluoride (F) ions in its crystal structure. This fluorine substitution increases its resistance to acid dissolution compared to other apatite minerals, making fluorapatite a valuable source of phosphate for fertilizer production.