and Norse deities (vanadium for the goddess Vanadis and thorium for the god Thor). Some elements were named for aspects of the history of their discovery. In particular, technetium and promethium were so named because the first samples detected were artificially synthesised; neither of the two has any isotope sufficiently stable to occur in nature on Earth in significant quantities. The connection to the Titan Prometheus was that he had been fabled to have stolen fire from the gods for mankind. Discoverers of some elements named them after their home country or city. Marie Curie named polonium after Poland; ruthenium, gallium, germanium, and lutetium were based on the Latin names for Russia, France, Germany, and Paris. Other elements are named after the place where they were discovered. Four elements—terbium, erbium, ytterbium, and yttrium—were named after the Swedish village Ytterby, where ores containing them were extracted. Other elements named after places are magnesium (after Magnesia), strontium, scandium, europium, thulium (after an old Roman name for an unidentified northern region), holmium, copper (derived from Cyprus, where it was mined in the Roman era), hafnium, rhenium, americium, berkelium, californium, and darmstadtium. For the elements up to 92 (uranium), naming elements after people was discouraged. The two exceptions are indirect, the elements being named after minerals that were themselves named after people. These were gadolinium (found in gadolinite, named after the Finnish chemist Johan Gadolin) and samarium (the mineral samarskite was named after a Russian mining engineer, Vasili Samarsky-Bykhovets). Among the transuranium elements, this restriction was relaxed; there followed curium (after the Curies), einsteinium (Albert Einstein), fermium (Enrico Fermi), mendelevium (Dmitri Mendeleev), nobelium (Alfred Nobel) and lawrencium (Ernest Lawrence). Relation to IUPAC standards IUPAC has established international standards for naming elements. The first scientist or laboratory to isolate an element has the right to propose a name; after a review process, a final decision is made by the IUPAC Council. In keeping with tradition, names can be based on a mythological concept or character, astronomical object, mineral, place, property of the element or scientist. For those elements that have not yet been discovered, IUPAC has established a systematic name system. The names combine syllables that represent the digits of the atomic number, followed by "-ium". For example, "unununium" is element 111 ("un" being the syllable for 1). However, once the element has been found, the systematic name is replaced by a trivial one, in