Limited Edition 550ct Turquoise beads 18" Necklace with sterling silver clasp and Certificate

length: 18.0 inches / 460mm   
Sterling silver mark on clasp: 925 TGGC (THE GENUINE GEMSTONE COMPANY) 

Condition: seen photos

Story: 

Turquoise is rare and valuable in finer grades and has been prized as a gem and ornamental stone for thousands of years owing to its unique hue.
Bibi-Khanym Mosque with turquoise domes in Bukhara, Uzbekistan
In many cultures of the Old and New Worlds, this gemstone has been esteemed for thousands of years as a holy stone, a bringer of good fortune or a talisman. The oldest evidence for this claim was found in ancient Egypt, where grave furnishings with turquoise inlay were discovered, dating from approximately 3000 BC. In the ancient Persian Empire, the sky-blue gemstones were earlier worn round the neck or wrist as protection against unnatural death. If they changed colour, the wearer was thought to have reason to fear the approach of doom. Meanwhile, it has been discovered that turquoise can change colour. The change can be caused by light, or by a chemical reaction brought about by cosmetics, dust or the acidity of the skin.
Turquoise is a stone and colour that is strongly associated with the domes and interiors of large mosques in Iran, Central Asia and Russia.

*R = Reconstruction
Enhancement by use of heat, pressure, and/or solvents to fuse small pieces of a gem together into a larger whole. 

Gemstone - Turquoise
Enhancement - Reconstructed (R)
Prevalence - Occasional
Purpose - To Produce Stones That Are Available To Set Into Jewellery
Durability / Stability - Very Good
Detection - Detectable By A Qualified Gemologist Without Using Sophisticated Equipment
Care & Cleaning - No Specific Care Required