Final answer:
The gemstone that results from biomineralization is the pearl. This process involves living organisms producing minerals, and pearls are created by mollusks as a defense mechanism.
Step-by-step explanation:
The common gemstone that results from biomineralization is c. pearl. Biomineralization is a process by which living organisms produce minerals, often to harden or stiffen existing tissues. Pearls are formed inside the shell of certain mollusks as a defense mechanism against a potentially threatening irritant such as a parasite inside the shell, or an attack from outside, injuring the mantle tissue. The mollusk creates a pearl sac to seal off the irritation. Pearls are composed mostly of aragonite (a form of calcium carbonate) and conchiolin. Unlike gemstones that are mined from the earth like diamonds, sapphires, and garnets, pearls are formed inside living creatures.