Rubies and Sapphires in Western Australia

This rock is a corundum rock from Western Australia. Photographed from the Geological Museum

Both Rubies and Sapphires are rare forms of the mineral called corundum. Corundum is a very hard mineral, the second hardest mineral after diamonds. Ruby and sapphire are transparent, coloured varieties of the mineral called corundum and are highly prized as gems.

Sapphires

Sapphire means 'beloved of the planet Saturn'.

In Persian mythology people believed that the Earth sat on a huge sapphire, so this made the sky blue. But in ancient Greece sapphires were considered symbols of honesty and trustworthiness.

Sapphire commonly occurs as barrel-shaped, or pyramidal crystals.

A spectacular yellow sapphire of 217.5 carats was found in 1946 at Willows in Queensland Australia.

Small amounts of iron and titanium are responsible for blue, yellow and green sapphires. The most abundant source of blue and yellow sapphires is from Australia.

Rubies

Ruby means 'red'.

Ancient peoples thought that rubies were able to stem the flow of blood from a deep wound and warriors wore them close to their skin in battle.

Rubies commonly occur as tabular crystals.

Crystals of rubies and sapphires from river gravels are usually water worn and rounded.

Rubies, today, are mined in central Africa.

Traces of chromium give ruby its rich red colour.

Small grains of corundum are called emery and are used on nail files.

Text;

"Fashioning the Stone" by Alex Bevan.

Check out these links for more information on Rubies and Sapphires

http://www.bsu.edu/teachers/academy/gems/archives/corundum.html
http://mineral.galleries.com/minerals/gemstone/ruby/ruby.htm and http://mineral.galleries.com/minerals/gemstone/sapphire/sapphire.htm We are not promoting that you buy anything on the internet.

Assignment: Why are rubies and sapphires always talked about together? What is the difference between these two gemstones? Which one do you think is more valuable? Which one is your favourite gemstone?