Jadarite is a white, powdery, non-radioactive monoclinic mineral, whose chemical formula is sodium lithium boron silicate hydroxide: LiNaSiB3O7(OH) or Na2OLi2O(SiO2)2(B2O3)3H2O. It was discovered in November 2006, in drill holes in the Jadar Valley (Serbian Cyrillic: Јадар, Yaddar) in Serbia, from which it is named. It was confirmed as a new mineral after scientists at the Natural History Museum in London and the National Research Council of Canada conducted tests on it. Exploration geologists from Rio Tinto Exploration discovered the mineral as small rounded nodules in drill core, and after being unable to match it with previously known minerals enlisted the expertise of Dr. Chris Stanley, from the Natural History Museum, who later described it as being unique to mineralogy.
The new mineral, unlike the fictional material in the movie, does not contain fluorine, does not emit electromagnetic radiation, and is white rather than green (although, in the Superman comics, there is a white colored variety of kryptonite). In all other respects the chemistry matches that of the rock containing kryptonite in the movie. The jadarite fluoresces a pinkish-orange color when exposed to UV light.