Robert Michael was given several pieces of Blue Chalcedony (pronounced "kal Sed' nee") from a collector who said the material was mined just North of Crawford, Nebraska.  Robert cut the Chalcedony into 12x12mm heart-shaped Cabochons and set them in Sterling Silver Pendants.
 
Chalcedony is a mixture of tiny (microcrystalline or cryptocrystalline) Quartz crystals and small quantities (trace elements) of other minerals.  Blue chalcedony occurs in a range of blue hues, from pale to darker blue, some with tints of gray and others with tints of pink. The color is generally attributed to the interference of light caused by microscopic voids between the individual molucles in the stone, a phenomenon known as “scattering”.