Rocks are made up deposited minerals that form and condense into rocks
An Olympic decoration is granted to effective contenders at one of the Olympic Amusements. There are three classes of decoration: gold, granted to the victor; silver, granted to the first sprinter up; and bronze, granted to the second sprinter up.
Explanation:
When magnesium metal burns is heated i the air it forms magnesium oxide.The balanced chemical reaction is given as:

2 moles of magnesium metal when reacts with 1 moles of oxygen it gives 2 moles of magnesium oxide which is white in color.
Some times along with formation of magnesium oxide small amount of magnesium nitride also produced due to which magnesium oxide appears grey in color .The balanced chemical reaction is given as:

3 moles of magnesium combines with 1 mol of nitrogen gas to to give 1 mol of magnesium nitride.
Answer: Luster (happy to help)
Explanation: Luster is the property of minerals that indicates how much the surface of a mineral reflects light.