Carbon : Diamond :: Corundum :?

As Peacock is the national bird of India, similarly Bear is the national animal of Russia.

As Ornithologist is a specialist of Birds similarly Archealogist is a specialist of Archealogy.

As cat has Paw similarly Horse has Hoof.

As Water of a River flows similarly water of Pool is Stagnant.

As 'Architect' makes 'Building' similarly 'Sculptor' makes 'Statue'.

As Myopia is disease of eye similarly pyorrhoea is a disease of teeth.

As Chairman is the highest authority in a conference similarly Editor is in Newspaper.

As safe ans secure have same meaning in the same way protect and guard have same meaning.