Material properties of diamond these are known as ballas and are important to industry as they lack the cleavage planes of single-crystal diamond. Carbonado is a similar opaque microcrystalline form which occurs in shapeless masses. Like ballas diamond, carbonado lacks cleavage planes and its specific gravity varies widely from 2.9 to 3.5. Bort diamonds, found in Brazil, Venezuela, and Guyana, are the most common type of industrial-grade diamond. They are also polycrystalline and often poorly crystallized; they are translucent and cleave easily. Because of its great hardness and strong molecular bonding, a cut diamond's facets and facet edges appear the flattest and sharpest. A
Rock Hawk Rock Hawk Rock Hawk Effigy Mound is an archaeological site in Putnam County, Georgia, United States. () It consists of thousands of pieces of quartzite laid in the shape of a large bird. Although it is most often referred to as a hawk, scholars do not know exactly what type of bird the original builders intended to portray. Only two such effigy mounds have been found east of the Mississippi River. The other, known as Rock Eagle, is also located in Putnam County, approximately thirteen miles to the northwest. () The physical condition of Rock Hawk is far below that