Which of the following statements is incorrect?
APrecious rocks like ruby and emerald are used for making jewellery.
BMarble is formed by cooling of lava.
CBlack gold is another name of petroleum.
DShale is used to make tiles and bricks.
Which of the following statements is incorrect?
APrecious rocks like ruby and emerald are used for making jewellery.
BMarble is formed by cooling of lava.
CBlack gold is another name of petroleum.
DShale is used to make tiles and bricks.