The Chemical Element Chromium

What is Chromium?

Chromium is a steely grey coloured lustrous metal discovered in 1797.  Although extremely hard it's also brittle.

On Mohs scale of hardness it grades 8.5.

This metallic chemical element is often used as an alloy because of its exceptional hardness and resistance to tarnishing.

When alloyed with iron chromium prevents rust.  When alloyed with steel it becomes known as stainless steel.  Chromium helps steel become more resistant to corrosion and discolouration.  

Chromium has a high melting point and is relatively flexible.  It has no odour or taste.

It's an essential mineral that's needed by the human body but only in very small amounts. 

The name "chromium" comes from the Greek word "chrōma" meaning "colour" because all chromium compounds are colourful.

When present in corundum it turns this mineral red.  Gem grade red corundum is ruby.

The green colour of emerald comes from chromium, vanadium and beryllium.