Geislavirk frumefni

Einsteinium: HólmblýEinsteinium is the heavier brother of Holmium (named after Stockholm) in the Lanthanide series and displays properties similar to its lighter counterpart. The addition 'blý' is used to position an element after 'lead' and 'bismuth'. If Einsteinium desintegrates, the largest part of it will ultimately desintegrate into lead.)
Nobelium: Elfráðsblý

Californium: nifteindagull
The discoverers named the new element after California and the University of California. The element directly above element 98 in the periodic table, dysprosium, has a name that simply means "hard to get at" so the researchers decided to set aside the informal naming convention. They added that "the best we can do is to point out [that] ... searchers (for gold)a century ago found it difficult to get to California (the "gold rush state")."
Californium is a very strong neutron emitter. It is therefore used as a portable neutron source for the discovery of metals such as gold and silver. These are all reasons enough to use the word 'gold' to designate Californium in the figurative sense of 'valuable and costly substance' as in 'black gold' for 'oil' . Californium is the (extremely expensive http://www.straightdope.com/columns/read/294/whats-the-most-expensive-thing-in-the-world ) 'neutron-emitting gold': nifteindagull, this word can only mean californium, even if heavier new ones are found in the future, Californium was the original 'king of the neutron transmitters'. Amazing! Californium is apparently translatable with medieval Icelandic word-building blocks! Eureka

Polonium (maríublý, púlín) First of all I want to say that I'm abhorred about the cowardly act that brought this man, himself being a crook or not, to his death-bed. No hominid who has evolved somewhat beyond the average ringtail-maki as for moral conscienceness would ever commit such a crime.
OK, that being said, now about the element itself. Polonium is situated just 2 places to the right of lead (BLÝ) on the periodic system. It is an unstable radioactive metal that desintegrates into lead. It was discovered by Marie Curie, who named it after her country Poland. The abbreviation of 'Poland' on car number plates is PL. The term maríublý is already robust enough a term. If the word has to be constructed in the same style as most other names, where the ending -ium is replaced by -ín (natrín, kalín, kalsín, why not calling polonium PÚLÍN, instead of 'pólon', after the oldest Icelandic form Púlínaland, mentioned in the Þiðreks saga af Bern: En er Vilkinus konungr hefir stýrt þessu ríki um stund, þá býr hann her sinn ok ríðr með ótal riddara ok annarra hermanna út í Púlínaland ok á þar margar orrostur ok stórar bæði.
Radium: Maríuglóð

Maríuglóð (radium) er mun geislavirkari en heljarblý (Plutonium)! Discovered by Marie Curie (maríu-), radium is so radioactive that it glows in the dark (-gló). It is even possible to call your daughter after Radium: Þórleif or Þórleifur, as radium isotopes are mostly so-called daughter products of the element Thorium, named after the God Thor (my suggestions for an Icelandic name for Thorium: þórefni or þórsblý).

Astatine: óst, völtungur

The name astatine comes from the Greek word astatos, meaning "unstable," to imply the created isotope's unstability towards radioactive decay. The icelandic word for unstable is óstöðugur, which sounds similar while being etymologically related to the Greek word. The neologism óst is an abbreviation of the adjective. It is a reductionist neologistic style comparable to the formation of ál for aluminium. In this respect, The Icelandic óst is proportionate to the English astatine in the same way as ál is proportionate to aluminium. Judging from its similarity to the nouns ást and ósk, the most appropriate gender for óst is probably the feminine one: óst, óst, óst, óstar.
Another possibilities to iceladicize this name is völtungur, derived from valtur, a synonym of óstöðugur, because it rhymes on söltungur (halogene, salt-former; astatine belongs to the halogen group of elements), derived from salt, because valtsöltungur was too long.
Actinium: þórál
Actinium is the 'aluminium next to thorium' (Aluminium is used here in the sense of 'trivalent chemical element', because it happens to be the primordial and most abundant trivalent metallic element in the universe and the first of its kind (boron is not a metal) on the periodic table. The first element 'þór-' refers to its closest actinide brother situated right next to it on the periodic table, the relatively superstable thorium.
actinides: þórálungar or dulmálmabræðir (brothers of the 'concealed metals', my term for the erroneous term 'rare earths' (dulmálmar). The rare earth elements only seem to be rare because they aren't concentrated as ores in particular locations earth and probably on other rocky planets. They are, instead, widely distributed throughout the earth's crust, which makes it difficult to obtain them, hence the original misconception about their terrestrial abundance, which is, actually, relatively high.
The closest brothers of the rare-earth elements, all of which, except for Scandium and Yttrium belong to the Lanthanide group (Leyndarmálmar) are the actinides, hence the term dulmálmabræður.
Proactinium: þórálsmóðir (proto- (for-) + þórál (actinium), because the longest-lived protactinium isotope desintegrates into an isotope of actinium).
Lawrencium: Lafransblý An artificially made chemical element, named after Ernest Lawrence, inventor of the cyclotron. The surname Lawrence originates from 'Laurentius', the original Icelandic form of which is 'Lafrans' (as in Lafransmessa). All elements after lead can be named with compounds of which the second element is 'blý'. This is a kind of positioning technique: heljarblý (Plutonium, named after the female Nordic equivalent of the male roman underworld god Pluto), Maríublý (Polonium, the radioactive second element after lead that was discovered by Marie (Maríu-) Curie), Frakkblý (Francium, named after France). Stumbling on a possibility to denominate a superheavy transuranium actinide that scientists succeeded in creating only recently and merely in picogram amounts with words from the medieval Icelandic lexical stock is an exciting experience.

Promethium: Eldþjófsefni, gervidulmálmur, promeþeifsefni
Promethium (gervidulmámur) is the only articficially made 'rare earth element' (dulmálmur as I call them, because is it a more accurate dsignation of this goup of metals, that only seem to be rare because they aren't concentrated on particular locations where they can be easily mined. They are, instead, widely distributed throughout the earth's crust, which makes it difficult to obtain them, hence the misconception about their terrestrial abundance, which is, actually, relatively high.)
If you google 'fire thief', you will find almost always references to Prometheus, the Greek mythological figure, who stole the fire from the gods. The compound eldþjófur cannot mistakingly refer to anything else than Prometheus. That's why I went for Eldþjófsefni instead of Prómeþeifsefni wasn't hardcore enough for me.
Berkelium: Birkilóarefni, Birkilængur
This artificially made transuranium element was named after Berkeley, which means 'Birch-tree wood or clearing', from the Old English beorc and leah, the Icelandic equivalents of which are 'björk, birki- in compounds' and 'ló': 'Birkiló'. The name of the element becomes then: birkilóarefni or birkilængur (contraction of Birkilængur, as in the personal name Klængur, derived from 'kló-' (claw) with addition of -ingur).

Americium: níþungt álI originally called this element 'níþungt ál' because the most stable isotope of Americium (atomic weight 243) is exactly 9 times as heavy as ordinary aluminium nuclei (atomic weight 27 = 243/9). I dropped this term because an Icelandic friend of mine rejected it because of a confusion with NÍÐÞUNGUR, which means 'very heavy' (níð- is an intensifying prefix). On another occasion, I also asked an Icelandic chemist and he had no objection. Yes, he told me, it sounds like níðþungur, but that doesn't mean you can use níþungur in the meaning 'nine times as heavy'. What's more, Americium sounds somewhat like Aluminium. Aluminium is the primordial, most abundant trivalent element and I use the Icelandic name ál as a building block to designate other trivalent elements throughout the periodic system.
Curium: heljarblýsmóðir (the mother product of 'hejarblý' (Plutonium)
Fermium: Erblý (Er from Erbium + blý)Erbium is the lighter brother of Fermium, named after ytterby (Ytribær), a place in Sweden after which three elements are named: ytterbium, terbium and erbium. The first element is just 'Er-' as in the international abbreviation for Erbium, the second is 'blý' and refer to the position of Fermium in the regiion beyond blý and that the the most part of the majority of its isotopes would eventually desintegrate into lead.Mendelevium: Tílisblý (We can name this element after its lighter lanthanide brother which have similar properties: Thulium, named after Thule, named Tíli (Tílis-) in the 'Landnámabók'. The second element is 'blý' used as a positioning marker for all elements heavier than lead.)