Native American Navajo Sterling Silver and Turquoise Pin/Brooch measures approximately 3" x 2.5".

This piece dates after 1940 because it is stamped AC Sterling.  Before this date Native Americans used silver from molten coins and did not stamp the jewelry.  Here, the artist used sterling silver sheet, twisted square wire, cold steel stamps, and has fashioned scalloped and bumped out accents to wrap around the turquoise stone. 

This particular piece of turquoise looks like Kingman spiderweb due to the copper variations in the stone. Or could be Pilot Mountain due to the large brown veining in the stone.  

The Kingman Turquoise Mine is one of the oldest and highest producing turquoise mines in America. It was originally discovered by prehistoric Indians well over 1000 years ago. Kingman Turquoise is known for its beautiful sky blue color and produces many variations of blue Turquoise. The Kingman Turquoise mine also produces green Turquoise from the Turquoise Mountain side of the mine. Kingman Turquoise has been the biggest supplier of Turquoise to the southwestern turquoise jewelry industry for nearly as long as the American Turquoise Jewelry industry has existed. In fact, the Kingman Turquoise mine was once part of a turquoise boom around 1000 AD when the Mayan culture was using a lot of Turquoise for self adornments and ceremonial items. Today, as in the old times, blue turquoise from Kingman, Arizona is king, even though the mine produces all colors of Turquoise and green turquoise is almost becoming blue Turquoise's equal in popularity these days.