(1) Moorti means Image or idol. In Vaidik and Upanishadik times Hindu worshipped God though chanting of Mantra and by performing Yagya and Havan. Later on they began to create three dimensional images of their deities in marble, any other stone, terra cotta, and worship the deity through this idol. The most popular deities worshipped in this way are Vishnu, Raam, Krishn, Ganesh, Lakshmee, Hanumaan, Durgaa, Saraswatee. Shiv is also sometimes carved in a human form, but at other times he is represent by a cylinderical stone which gradually becomes pointed at the top - this symbol is called Ling.
[Aangiras, p 293]

Naarad Jee said to Ambareesh - "A statue when it has been established properly (by Praan Pratishthaa) is called idol. Such Bhagavaan's idols may be of eight types - metal, iron, stone, clay, picture, sand, Manomayee (as one likes), and of gems. Again they may be of two types - movable and immovable. A Bhakt should worship the one which is easily available to him.

According to Bhavishya Puraan, 1/18, Naarad Jee told Saamb that the idol may be of 7 types - Gold, silver, copper, stone, clay, wood, or picture.

In Bhaagvat Puraan, 11/22, Krishn says to Uddhav - "My idols are of eight types - stone, wooden, metal; soil or sandalwood etc, picture, sand, in the heart, and gem-studded. Or there are two other types of my idols - according to moving and non-moving type. When you worship non-moving type of idols, then do not do Aavaahan and Visarjan (concluding) daily, but you have a choice with moving idol, you may do it or you may not do it. Still with sand idol you must do Aavaahan and Visarjan daily. Soil and sandal idols should not be given bath, just wipe them, but all other idols should be given bath. Although My Poojaa is done with special materials, but Nish-Kaam devotees may worship Me in their hearts or whatever is available. Bath, clothes, jewelry etc are used to worship stone or metal idols."