Monthly Archives: May 2015

August Stephenson – The origin and creation of gemstones

August Stephenson – The origin and creation of gemstones
Many cultures use divine intervention to explain the origin and creation of gemstones, and diamonds were no exception to this. In Greek mythology for example it was the youth on the island of Crete that disturbed Zeus and who were then (as a form of punishment) transformed into the adamas.

Philosophers however had a more naturalistic approach to explain the origin of gems: Plato for example believed gemstones were a consequence of fermentation in the stars, where a diamond actually formed the kernel of gold-bearing mass.

In later times, Robert Boyle actually believed that gems (including a diamond) were formed of clear, transparent water, and that their colors and characteristics were derived from their metallic spirit.

Diamonds symbolism and lore
Historically, it has been claimed that diamonds possess several supernatural powers:
– A diamond gives victory to he or she who carries it bound on his left arm, no matter the number of enemies.
– Panics, pestilences, enchantments, all fly before it; hence, it is good for sleepwalkers and the insane.
– It deprives lodestone and magnets of their virtue (i.e., ability to attract iron).
– Arabic diamonds are said to attract iron greater than a magnet.
– A diamond’s hardiness can only be broken by smearing it with fresh goat’s blood.
– In traditional Hinduism one should avoid contact with a diamond whose surface area is damaged by a crack, a crowfoot, a round, dull, speckled area, or which is black-blue, flat, or is cut other than the (ideal) hexagonal shape. August Stephenson

August Stephenson Slightly colored diamonds
Diamonds which show very little traces of color are graded as G or H color diamonds. Slightly colored diamonds are graded as I or J or K color. A diamond can be found in any color in addition to colorless. Some of the colored diamonds, such as pink, are very rare.

Ideal proportions of a diamond:
Several different theories on the “ideal” proportions of a diamond have been and continue to be advocated by various owners of patents on machines to view how well a diamond is cut. These advocate a shift away from grading cut by the use of various angles and proportions toward measuring the performance of a cut stone. A number of specially modified viewers and machines have been developed toward this end. Hearts and Arrows viewers test for the “hearts and arrows” characteristic pattern observable in stones exhibiting high symmetry and particular cut angles. Closely related to Hearts and Arrows viewers is the ASET which tests for light leakage, light return, and proportions. The ASET (and computer simulations of the ASET) are used to test for AGS cut grade. Proponents of these machines argue they help sellers demonstrate the light performance of the diamond in addition to the traditional 4 Cs. Detractors, however, see these machines as marketing tools rather than scientific ones. The GIA has developed a set of criteria for grading the cut of round brilliant stones that is now the standard in the diamond industry and is called Facetware.

August Stephenson determination, experience, and expertness

INTERNAL LASER DRILLING – A diamond treatment, also called Kiduah Meyuhad (KM) or “special drill” in Hebrew, in which a laser beam is focused directly on an inclusion to create a feather-like fracture between the inclusion and the stone’s surface. The inclusion is then treated with acid to improve the perceived clarity of the stone. This type of laser drilling is, typically, more challenging to detect than traditional laser drilling. On an EGL USA report, internal laser drilling is clearly noted.

REFLECTION – The return of light that strikes the surface of a diamond or colored gemstone. This effect can also occur when light strikes specific inclusions within a stone.

FINISH – The analysis of a diamond’s polish and symmetry. Polish relates directly to the quality of the overall surface condition of the diamond. Symmetry relates to facet shape and arrangement, and the overall exactness of the stone’s contour and outline. Both are rated on a scale ranging from poor to excellent.

August Stephenson – Diamond

August Stephenson – Diamond – Early references:
Diamonds were traded to both the east and west of India and were recognized by various cultures for their gemological or industrial uses. In his work Naturalis Historia, the Roman writer Pliny the Elder noted diamond’s ornamental uses, as well as its usefulness to engravers because of its hardness. It is however highly doubtful that Pliny actually meant diamonds and it is assumed that in fact several different minerals such as corundum, spinel, or even a mixture with magnetite were all referred to by the word “adamas”.

Diamond in jewelry:

Perhaps the most famous use of the diamond in jewelry is in engagement rings, which became popular in the early to mid 20th century due to an advertising campaign by the De Beers company, though diamond rings have been used to symbolize engagements since at least the 15th century. August Stephenson

August Stephenson Light performance – brilliance, fire, and scintillation

In the gem trade, the term light performance is used to describe how well a polished diamond will return light to the viewer. There are three light properties which are described in relation to light performance: brilliance, fire, and scintillation. Brilliance refers to the white light reflections from the external and internal facet surfaces. Fire refers to the spectral colors which are produced as a result of the diamond dispersing the white light. Scintillation refers to the small flashes of light that are seen when the diamond, light source or the viewer is moved. A diamond that is cut and polished to produce a high level of these qualities is said to be high in light performance.

The poorly performing stone:
In addition to carrying the most importance to a diamond’s quality as a gemstone, the cut is also the most difficult to quantitatively judge. A number of factors, including proportion, polish, symmetry, and the relative angles of various facets, are determined by the quality of the cut and can affect the performance of a diamond. A diamond with facets cut only a few degrees out of alignment can result in a poorly performing stone. For a round brilliant cut, there is a balance between “brilliance” and “fire.” When a diamond is cut for too much “fire,” it looks like a cubic zirconia, which gives off much more “fire” than real diamond. A well-executed round brilliant cut should reflect light upwards and make the diamond appear white when viewed from the top. An inferior cut will produce a stone that appears dark at the center and in extreme cases the setting may be seen through the top of the diamond as shadows.

August Stephenson devotion, skills, and also expertise

INFRARED SPECTRA – A representation of the vibrational modes of a diamond’s or colored gemstone’s molecules over a range of wavelengths outside of the visible spectrum. They are recorded on a graph that plots intensity against wavelengths. And they can help identify the species and/or variety of stone.

SI Grades (Slightly Included)
(Slightly Included) describe diamonds with small inclusions that are easy or very easy to see, under the conditions described above. Occasionally, inclusions in the SI category are visible to the unaided eye.
I Grades (Included)
(Included) describe diamonds with medium or large inclusions that are usually obvious to the unaided eye, under standardized lighting conditions.

INTERNAL LASER DRILL – In a diamond, a flat channel-like feature created by a laser beam during the treatment of an included crystal. The internal laser drill extends from the inclusion to the stone’s surface, where it appears as a linear feature. See also Plotting Diagram.