Neutron stars may house enormous diamond-like centers, according to a study published today in the Physical Review Letters. The finding did not result from cosmic mining efforts. Rather, researchers were probing on a far smaller scale, investigating the life expectancy of subatomic quarks. Different kinds of quarks exhibit differing stabilities. The so-called strange quark, for example, is generally far less stable than "up" and "down" quarks. In the high-density environment inside a neutron star, however, scientists expect the strange quark to have an easier time of it. The new research, conducted by physicists Krishna Rajagopal and Frank Wilczek of M.I.T., shows just how much better the strange quark should fare inside a neutron star.

Scientists have guessed that within neutron stars, the matter is made from up quarks, down quarks and slightly fewer strange quarks, compressed to extraordinary densities. Conventional wisdom holds that such a quark-matter collective would have an overall positive electrical charge. As a result, the material should attract electrons and create an opaque, metallic quark clump at the heart of the neutron star. But Rajagopal and Wilczek's calculations indicate that in fact the strange-quark population matches that of its up and down counterparts. The quark-matter collective in the neutron star would therefore be electrically neutralelectron-free and transparent.

"Thus, it seems likely that inside each neutron star is a 'Diamond as big as the Ritz,'" Wilczek remarks. "Actually, much bigger, and a million billion times as dense." Although the star's core would be neither solid nor crystal nor faceted, apparently it would reflect some light at its boundaries and otherwise resemble a diamond.