Which of the following is produced by a pearl-bearing mollusk?

The correct answer is mother-of-pearl, which is also known as nacre. This substance is a product of pearl-bearing mollusks, such as oysters and certain types of mussels. When an irritant, like a grain of sand, enters the mollusk, it secretes layers of nacre around the irritant as a defense mechanism. Over time, these layers build up to form not just pearls but also the inner shell lining of the mollusk, which is referred to as mother-of-pearl.

Mother-of-pearl is prized for its iridescent appearance and is often used in jewelry and decorative items. It has a unique structure that reflects light in various colors, making it highly sought after in the market.

The other options listed do not originate from mollusks. Jadeite is a type of jade, a mineral primarily composed of the silicate mineral jadeite itself and is found in metamorphic rocks. Garnet is a group of silicate minerals used as gemstones, while quartz is a common mineral formed from silicon and oxygen, found abundantly in the Earth's crust. None of these options are related to the production of mother-of-pearl or pearls, confirming that mother-of-pearl is the only correct choice in