I’m always a little skeptical when I hear astronomers talking about specific compositions of matter out in the universe.  The recent gushing press release from Reuters about a diamond planet orbiting a neutron star just adds to my burden of disbelief. 

I truly hope there is more evidence than that revealed in the press release. That is, the assignment of the diamond allotrope of carbon based on density (3.53 g/cm3).  The report seems to express amazement that the planet is “so dense”.  A specific gravity of 3.53 is not that high. Many other compositions are possible.  Perhaps Reuters should look at high density objects closer to home.