This diadem was a gift of Emperor Napoleon to his bride Marie Louise on the occasion of their wedding in 1810. It is displayed in the Smithsonian Museum of Natural History
The major source of turquoise is the western United States.
These samples of turquoise are displayed in the Smithsonian Museum of Natural History. Turquoise is a phosphate mineral of copper and aluminum . It has the composition CuAl6(PO4)4(OH)8.4H2O. This sample is about 10 cm wide and is from Los Cerillas, New Mexico.
At left is a turquoise Zuni bracelet from Arizona.
This sample is about 7cm wide and is from Lynch Station, Virginia.