sentence: People make synthetic diamonds.
sentences_before: Many of them are clear, but some of them have colors, like yellow, red, blue, green and pink. Big diamonds are very rare, and are worth a lot of money. This is because a diamond is very useful - it is very hard and it spreads light very well. There are natural and synthetic diamonds. The earth makes natural diamonds.
sentences_after: Diamonds are the hardest natural substance known to man.
concept_name: People
headings: Diamond
categories: Gemstones Carbon Birthstones