what material was the most surprising planet made out of

Question: what material was the most surprising planet made out of
- Keywords:
  matter,
  planet,
  space
Asked by anon-226526 to joannabarstow on 19 Nov 2019.
- Joanna Barstow answered on 19 Nov 2019:
  
  There have been claims that some planets are very carbon rich. Diamonds are a form of carbon, so these planets are sometimes referred to as ‘diamond planets’. However, those claims are still up for debate.

Question: what material was the most surprising planet made out of