Hardness: 9

A Ruby is a pink to blood-red gemstone  a variety of the mineral corundum (aluminium oxide]. The common red color is caused mainly by the presence of the element chromium. Its name comes from ruber, Latin for red. Other varieties of gem-quality corundum are called sapphires. Prices of rubies are primarily determined by color. The brightest and best "red" called pigeon blood-red, commands a huge premium over other rubies of similar quality. After color follows clarity: similar to diamonds, a clear stone will command a premium, but a ruby without any needle-like rutile inclusions will indicate that the stone has been treated one way or another. Cut and carat (size) also determine the price

TREATMENTS

Unless a ruby has a certificate as natural all Rubys should be considered to have had some lead glass treatment.This is usually stated as 'fissure cavity filled treatment' This treatment infuses leaded glass to fill in cracks and fissures which improves the appearance of the stone.In most cases the durabilty is not as strong as a natural stone.