Apatite Vs. Wollastonite

Apatite is a popular mineral group composed of a group of phosphates.^[1] Wollastonite is also a popular mineral and its chemical composition is calcium silicate.^[2]

Quick Facts on Differences of Apatite and Wollastonite

For a quick recap of the differences apatite and wollastonite:

• In terms of crystallography, apatite is hexagonal while wollastonite can be monoclinic or triclinic.
• For chemical formulas, apatite can be Ca5(PO4)3(F, Cl or OH) while wollastonite is CaSiO3.
• While both apatite and wollastonite is vitreous, in terms of luster, wollastonite can be pearly or silky.
• Apatite can be commonly red while wollastonite can be commonly green.
• Apatite's rarity is less rare than wollastonite.

Quick Facts on Similarities of Apatite and Wollastonite

The similarities of apatite and wollastonite include:

• Apatite and wollastonite both can be translucent or transparent.
• Apatite and wollastonite both streak white.
• Apatite's hardness overlaps with wollastonite - apatite is 5 and wollastonite ranges from 4.5 to 5 on the Moh's scale.

Summary of Apatite

Apatite is a mineral that is commonly found in igneous, metamorphic, and sedimentary rocks. It is made up of calcium phosphate, which is the same mineral that makes up our teeth and bones. Apatite can be identified by its green, blue, or yellow color, and its hardness of 5 on the Mohs scale. It can also be identified by its crystal structure, which is hexagonal.

Summary of Wollastonite

Wollastonite is a white to yellowish-brown mineral with a hardness of 4.5-5 on the Mohs scale. It is a calcium silicate mineral that is commonly found in metamorphic rocks such as skarns and contact metamorphic rocks. The mineral has a fibrous or needle-like crystal structure, which makes it easy to identify. It has a specific gravity of 2.8-3.1 and a refractive index of 1.62-1.64.

Table Comparison of Apatite vs Wollastonite