Instead, these giants may simply have dumped all their contents back into space, dispersing heavy elements like iron equivalent to the mass of 10 of our Suns.

BBC: Astronomers detect 'monster star'

In 1957, he and three colleagues wrote a paper showing how elements heavier than iron are produced.

ECONOMIST: Sir Fred Hoyle

In theory, making elements up to iron should not be hard.

ECONOMIST: Sir Fred Hoyle

Household waste, for example, would be reduced to pure carbon, oxygen and hydrogen, along with a handful of heavier elements (tungsten, iron, aluminium and so on) which could then be re-used.

ECONOMIST: Nuclear waste

Jake Matijevic was found to be high in elements consistent with the mineral feldspar, such as sodium and potassium, and low in elements such as magnesium and iron.

BBC: Nasa's Curiosity rover finds 'unusual rock'

Dr. SCHAWINSKI: So, in the very early universe, most of the elements that were made in the Big Bang were hydrogen and helium, and very few trace elements of heavier elements, like oxygen and iron and so forth.

NPR: What Makes Our Solar System Special?

Like other iron minerals, green rust readily absorbs dissolved elements onto its surface, but green rust is not only particularly efficient at this in many cases, it can also react with toxic dissolved trace metals to make them insoluble, and as a result, renders them in nontoxic forms.

MSN: What green rust did long ago to the big blue ocean

The team found that a majority of the samples contained elements known to be helpful, such as calcium, iron and zinc.

BBC: 'Patent medicines' study X-rays old-time remedies