A Visual Encyclopedia of the Periodic Table

92

Transition Metals

Forms

Iridium

Ir

77

77 77 115

State: Solid

Discovery: 1803

Iridium is the rarest natural element on

Earth: there is one iridium atom out of

every billion atoms in Earth’s rocks. This

dense metal can be found in its pure form in

nature as well as in other common ores that

contain nickel and copper. Iridium is present

in meteorites and other space rocks. A layer

of iridium-rich clay is found in Earth’s crust

all over the world, especially in the Badlands

of South Dakota, USA. Scientists believe

this small quantity of iridium in our planet’s

crust was deposited by the dust from an

Badlands National Parks,

South Dakota, USA

These rocks contain a

layer of iridium-rich clay.

Pu

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ir

id

iu

m

cr

ys

ta

ls

This metal

is 22 times as

dense as water.

This meteorite,

found in Oregon,

USA, contains just

0.00047% iridium.

W

il

la

m

et

te

m

et

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rit

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