Lapis Lazuli with its deep azure blue colour and often flecked with golden pyrite inclusions, was treasured by the ancient Babylonians and Egyptians and often worn by royalty. Lapis lazuli was widely used by Egyptians for cosmetics and painting.
Persian legend says that the heavens owed their blue colour to a massive slab of Lapis upon which the earth rested. Lapis Lazuli was believed to be a sacred stone, buried with the dead to protect and guide them in the afterlife.
In the Americas, the Incas, Molles, Diaguitas and other pre-Columbian cultures have, for thousands of years, used lapis lazuli to ornament masks and other artifacts. more....
A relatively soft stone, with a hardness of around 5.5 on the Mohs scale, lapis lazuli is one of the most valuable semi opaque stones. 
The stone is mined from deposits located at 3600 meters above-sea-level in the Andes Mountains in the area of Ovalle, Chile. In 1851, the location of this deposit was mapped, and in 1894 Las Flores de Los Andes was officially registered as a mining property of Chile.
For many people all over the world Lapis lazuli is considered a stone of universal truth and friendship. The blue stone is reputed to bring about harmony in relationships and to help its wearer being an authentic individual who may openly state his or her opinion.
Lapis takes an excellent polish and can be made into jewellery, carvings, boxes, mosaics, ornaments and vases. 
Many a cutter 'turns up his nose' when cutting lapis lazuli, for as soon as the stone comes into contact with the cutting-disc it gives off a typical smell. An experienced cutter can even tell from the odour how intense the colour is. When polishing this stone, he must handle it gently on account of its modest hardness and not subject it to much pressure. . 
Lapis lazuli is somewhat porous and should be protected from chemicals and solvents, never put Lapis in a chemical dip or ionic jewellery cleaner. Your best bet is to simply wipe it off with a barely damp cloth without soap. Lapis is not very hard at 5.5 and should be protected from other jewellery when stored to avoid scratches (i.e.. clean and store it as you would a pearl or Opal). 