The claims centre on a mineral with a high iron content called magnetite , which is found embedded in the Martian rock in an unusual form.
The sedimentary clasts also contain abundant opaque minerals, chiefly magnetite .
The replacement of the authigenic magnetite by hematite probably occurred at the same time as the specular hematite that surrounds the dolomite grains.
Chemically, Strain 121's respiration process reduces ferric iron to ferrous iron and forms the mineral magnetite , the source of most of the magnetic material deposited on Earth some two billion years ago.
Nearby is a magnet, composed of natural magnetite , that once belonged to Lomonosov.
Microscopic analyses reveal that the oxide mineralogy of the dolerites is dominated by magnetite and ilmenite.
In part, the hypothesis involved tiny grains of the naturally magnetic mineral magnetite , which is commonly found in basalt (a high-temperature volcanic rock that makes up oceanic crust).
The magnetite , uralite, and other minerals can be exposed by etching away the enclosing calcite with hydrochloric acid.
The new ‘evidence’ is tiny (one-millionth of an inch in diameter) crystals of magnetite , a magnetic oxide of iron.
In the left test tube, a magnet attracts magnetite , the byproduct of Strain 121's respiration of iron oxide and offers a tell-tale sign of life in the tube.