Ruby

Appearance:

Varying tones of red. Can be transparent, translucent or opaque.

Common variations...

Ruby is part of the Corundum group of stones and is almost identical to Sapphire in both chemistry and structure. Ruby is red whilst other colours of Corundum are known as Sapphire.

Esoteric beliefs and associations...

Associated with the planet Mars, the direction of South, and with the month of July. With strong red colouration, it is known for physical protection and strength in battle or conflict, along with improved health, courage and passion.

Other useful information...

In times past, 'ruby' was a designation of colour (from the Latin 'rubeus' meaning 'red'), including stones such as red spinel and garnet.

Physical properties...

Chemistry	Aluminium oxide. Pigment is chrome (red) and iron (shades of brown).
System/Structure	Hexagonal (prisms or tablets, rhombohedrons)
Refractive Index	1.766 - 1.774
Specific Gravity	3.97 - 4.05
Mohs' Hardness	9