57
Transition Metals
57
Chromium is named after chroma, the Greek
word for “colour”. Many minerals of chromium,
including chromite and crocoite, are brightly
coloured. An artificial form of crocoite, known
as “chrome yellow”, was once used in paints, but
it was banned when scientists discovered it to be
poisonous. Pure chromium doesn’t corrode
easily, so it is combined with iron and carbon to
produce stainless steel. Chromium also gives
gemstones, such as rubies, their deep-red
colour. Some motorcycles have chromium-
plated bodywork, giving them a shiny finish.
Chromium
Cr
24
24 24 28
State: Solid
Discovery: 1798
Forms Uses
This red colour is due
to the presence of tiny
amounts of chromium
oxide in the crystal.
The chromium
plating protects this
motorbike from rusting.
Ruby
Chromite Stainless steel kitchenware
This grater can resist
corrosion because it
contains chromium.
These large red
cr ystals contain
chromium and lead.
C
ro
co
it
e
This metal stays
shiny even when
exposed to air
and water.
Chromite is dark grey
to brown in colour.
Mo
torcycle
of pu
re
c
hr
om
iu
m
Labor
at
or
y^
sa
m
pl
e
056-057_Vanadium_Chromium.indd 57 02/12/16 6:52 pm