The Origin and Use of Diamonds
In Cape Province on the desert coast just south of the mouth of the Orange River, terrace deposits containing high-quality stones were discovered in 1927. Later similar deposits were found along the coast north of the Orange River in southwest Africa extending 50 to 60 miles up the coast. Elsewhere in Africa alluvial diamonds were found in French Angola, Ghana, French Equatorial Africa, and Sierra Leone. The discovery is in Tanganyika made that country a major producer. For many years British Guiana and Venezuela had a small production but Venezuela’s production eventually substantially increased.
Diamonds were found sparingly in various parts of the United States. Small stones occasionally were discovered in the stream sands along the eastern slope of the Appalachian Mountains from Virginia south to Georgia. diamonds were also reported from the gold sands of northern California and southern Oregon. These diamonds would eventually become recognized as EGL loose diamonds used for EGL diamond grading as well as valuable rings, necklaces, earrings, and bracelets.
Sporadic occurrences of diamonds were noted in the glacial drift in Wisconsin, Michigan, and Ohio. In 1906 the first diamond was found at a new locality situated near Murfreesboro, Pike County, Arkansas. The stones found there were not only in the detrital soil but also imbedded in the underlying peridotite rock in a manner quite similar to that of the South African occurrence. The Arkansas locality yielded about 40,000 stones but eventually became unproductive. In 1951 the old mine workings were opened to tourists who, for a fee, were permitted to look for diamonds. During the first six months, several small diamonds were thus found.
When it comes to other uses for diamonds other than luxury and jewelry; fragments of diamond crystals have been used to cut glass for many years. The fine powder is employed in grinding and polishing diamonds and other gem stones. Wheels are impregnated with diamond powder for cutting rocks and other hard materials. Steel bits are set with diamonds, especially the cryptocrystalline variety, carbonado, to make non conflict diamond drills used in exploratory mining for rough diamonds. The diamond is also used in wire drawing and in tools for the truing of grinding wheels.
The diamond is the most important of the gem stones, and only in modern times has it been put to other uses. Its value depends upon its hardness, its brilliancy, which is due to its high index of refractions, and to its “fire,” which is due to its strong dispersion of light into the prismatic colors. In general the most valuable are those flawless stones which are colorless or possess a blue/white color. A faint straw-yellow color, which diamonds often show, detracts much from its value.
Deep shades of yellow, red, green, or blue known as fancy stones are greatly prized, and fine stones of these colors bring very high prices. Diamonds can be colored deep shades of green by irradiation with high-energy nuclear particles, neutrons, deuterons, and alpha particles, and blue by exposing it to fast-moving electrons. A stone colored green by irradiation can be made a deep yellow by proper heat treatment. These artificially colored stones are difficult to distinguish from those of natural color.
To determine if a GIA diamond can be grouped with best value diamonds, one must consider the value of the cut diamond. It depends upon its color and purity, upon the skill with which it has been cut, and upon its size. A one carat stone weights 200 milligrams, and if cut in the form of a brilliant, would be 6.25 millimeters in diameter and four millimeters in depth. A two carat stone of the same quality would have a value three or four times as great.
were also reported from the gold sands of northern California and southern Oregon. These diamonds would eventually become recognized as EGL loose diamonds used for EGL diamond grading as well as valuable rings, necklaces, earrings, and bracelets.
Sporadic occurrences of diamonds were noted in the glacial drift in Wisconsin, Michigan, and Ohio. In 1906 the first diamond was found at a new locality situated near Murfreesboro, Pike County, Arkansas. The stones found there were not only in the detrital soil but also imbedded in the underlying peridotite rock in a manner quite similar to that of the South African occurrence. The Arkansas locality yielded about 40,000 stones but eventually became unproductive. In 1951 the old mine workings were opened to tourists who, for a fee, were permitted to look for diamonds. During the first six months, several small diamonds were thus found.
When it comes to other uses for diamonds other than luxury and jewelry; fragments of diamond crystals have been used to cut glass for many years. The fine powder is employed in grinding and polishing diamonds and other gem stones. Wheels are impregnated with diamond powder for cutting rocks and other hard materials. Steel bits are set with diamonds, especially the cryptocrystalline variety, carbonado, to make non conflict diamond drills used in exploratory mining for rough diamonds. The diamond is also used in wire drawing and in tools for the truing of grinding wheels.
The diamond is the most important of the gem stones, and only in modern times has it been put to other uses. Its value depends upon its hardness, its brilliancy, which is due to its high index of refractions, and to its “fire,” which is due to its strong dispersion of light into the prismatic colors. In general the most valuable are those flawless stones which are colorless or possess a blue/white color. A faint straw-yellow color, which diamonds often show, detracts much from its value.
Deep shades of yellow, red, green, or blue known as fancy stones are greatly prized, and fine stones of these colors bring very high prices. Diamonds can be colored deep shades of green by irradiation with high-energy nuclear particles, neutrons, deuterons, and alpha particles, and blue by exposing it to fast-moving electrons. A stone colored green by irradiation can be made a deep yellow by proper heat treatment. These artificially colored stones are difficult to distinguish from those of natural color.
To determine if a GIA diamond can be grouped with best value diamonds, one must consider the value of the cut diamond. It depends upon its color and purity, upon the skill with which it has been cut, and upon its size. A one carat stone weights 200 milligrams, and if cut in the form of a brilliant, would be 6.25 millimeters in diameter and four millimeters in depth. A two carat stone of the same quality would have a value three or four times as great.
Tags: non conflict diamond | non conflict diamond | egl diamond grading | egl diamond grading | best value diamonds | best value diamonds | egl loose diamonds | egl loose diamonds | rough diamonds | rough diamonds | gia diamond | gia diamond | carbonado | carbonado | diamond | color | color | carat | carat | cut | cut