Based on its density and carbon content, experts presume that it is crystalline and would, essentially, be made of diamond. Its small orbit, such that it could fit inside our sun, suggests that it's a remnant of a much larger star that lost its outer layers (Ben Hirschler, "Astronomers Discover Planet Made of Diamond," Reuters, Aug. 25, 2011).
While scientists can postulate the origins and materials of the universe, we can know its Creator: "When I consider Your heavens, the work of Your fingers, the moon and the stars, which You have ordained, what is man that You are mindful of him, and the son of man that you visit him?" (Psalms 8:3-4 Psalms 8:3-4  When I consider your heavens, the work of your fingers, the moon and the stars, which you have ordained;
 What is man, that you are mindful of him? and the son of man, that you visit him?
American King James Version×).
For more information on how to prove God's existence and learn more about how His creation was formed, please read our free booklets Life's Ultimate Question: Does God Exist? and Creation or Evolution: Does It Really Matter What You Believe?