A team of astronomers has discovered that the millisecond pulsar PSR J1719-1438 shows timing variations on a 2.17 hour timescale. These can be explained with a Jovian planet. However, because of the planet's short distance to the star, its density has to be more then 20 times that of Jupiter to avoid tidal disruption. The planet is most likely a remnant of a binary star which avoided complete destruction. The chemical composition, pressure and dimensions of the planet indicate that it is crystallized, or in other words, a very big diamond. More information can be found in the Science article Bailes et al 2011 or at Sky And Telescope.
A planet made of diamond.
A planet as massive as Jupiter that circles its pulsar star every two hours.
Would it glitter as you looked at it?
This knowledge is useless. It will plow no field, fluff no stock, nor quiet a crying child. It just makes the universe a larger and stranger place.
You may now return to your regularly scheduled programming.