Question

Precious red coral is/coral used in ornaments is
A. Astraea
B. Fungia
C. Corallium
D. Tubipora

Answer 1

Hint: Corallium rubrum is the precious red coral of great commercial use. Its skeleton is made of a substance called corallium which has a distinctive pink-orange color. It is highly valued because it is used for making ornaments.

Complete answer:
Red coral or precious coral is the common name of a genus of marine corals, Corallium. The characteristic feature of this precious coral is its durability and intense red or pink-orange coloured skeleton, which is highly precious and used for making a variety of jewelleries.

Among the given options
Astraea is marine coral also known as the star coral. They have an appearance of stone. They are found in colonies which are fixed and have a spreading nature. They secrete a skeleton which can be soft or hard and made up of calcium carbonate. It makes the red coral which is commonly used for gems.

Fungia is commonly known as plate coral or the Mushroom coral due its body morphology resembling a mushroom. They are found in various bright colours including white, red, pink, purple, yellow and blue and are usually popular with keepers of reef aquariums.

Tubipora is an organ pipe coral also called a soft coral. This species of coral has a soft body but has a unique, hard skeleton of calcium carbonate that contains many organ pipe-like tubes. They occur mostly in the Indian and Pacific Ocean.

So, the correct answer is option C.

Note: Corallium, commonly called pink or red coral, is the most valuable species of deep sea coral used in manufacturing of jewelleries and sculptures. Its value is enormous, often exceeding the value of gold.