Panna like all Gemstones, is valued according to its Color, Cut, Clarity and Crystal. Emerald is the grass-green type of Beryl.
Normally, in the grading of Gemstones, color is by far the most important criterion. However, in the grading of Panna, crystal is considered a close second. Both are necessary conditions. A fine emerald must possess not only a pure vibrant green hue, but also a high degree of transparency to be considered a top Gemstone.
The Swat pannas show light red to red through the Chelsea color filter and completely absorb short-wave ultra-violet radiation.
This gives the rock its Gemlike green color. Varying amount of iron also alters the color of the rock. It has a hardness of 7.5-8 and a refractive index of 1.57-1.59. However, it is not a Panna Gemstone recommended for 'everyday' rough use since it falls in the category of soft stone.
A chemical analysis of an Panna shows that chromium (which is the cause of the green of panna) and iron are prominent constituents in Swat Panna. The presence of relatively high iron content means that the Pannas from Swat do not show so red a fluorescence as some other Pannas as iron acts as a fluorescence quencher.
The cut of the stone is also significant. Emerald can have round, pear, oval shapes and the famous Panna cut i.e., Octagonal Cut is most preferred. Inclusions are almost an accepted fact in pannas. A skillful gem cutter is able to hide the inclusions while cutting a Gemstone and bring out its colour and glitter.
Deposits of the stone are also found in other parts of the world such as in Zambia, Zimbabwe, Madagascar and Nigeria. However Columbia and Brazil are the leading producers of panna today. The mines of Egypt, which supplied emeralds to Cleopatra, are not much into production today. This is one of the reasons why there is no legendry beauty in the world anymore. Panna is said to enhance and maintain beauty. If a woman wears lots of Pannas on her body she can stay young and attractive for a very long time. Among the foremost consumers of panna are USA and Japan who buy 75% of the world's cut Pannas.
Color is divided into three components: Hue, Saturation and Tone. The hue must be bright. Gray is the normal saturation modifier or mask found in Panna. A grayish green hue is a dull green.
Brazil has been supplying Pannas to the world market since the 1980s. Typical Brazilian pannas are Lighter and Yellowish. Pannas from Zimbabwe are smaller is size and lighter in shade. However the term 'African panna' is a misnomer. It simply denotes Green Fluorite.
The presence of chromium in panna is the absorption spectrum it displays, which is distinctive enough to enable the stone to be distinguished from any other gem species.
The only other stones of approximately an Panna Green that show a chromium spectrum at all resembling that of emerald are green Jadeite and Chalcedony stained with a chromium salt. In none of these is the doublet in the deep red nearly so sharp a colour as in Panna is visible.
Property of Panna, the refractive indices and SG vary perceptibly according to the locality where it is mined, due to variations in chemical composition. The inclusions, also, are often distinctive for each locality, and Gemologists will do well to familiarize themselves with these things if they wish to distinguish between the Pannas of one mine from another.
The natural beryl used for the faceted seed on which the hydrothermal synthetic overgrowth is grown. The refractive index of the coating varies a little from sample.
In Colombian stones, which constitute a high proportion of fine Pannas used in Jewellery, the most constant features are flat cavities with upper and lower margins jagged like a coarse saw, containing liquid, a bubble of gas, and a little cube of rock salt.
Pannas from the Sandawana panna mine in Zimbabwe have played quite an important role in the trade since their discovery in 1956. These are rich in chromium and thus a very deep and vivid green, which seen at its best in small stones.
Dark Green Panns have recently emanated from Pakistan, and these contain rather indeterminate inclusions, along which flakes of mika and small crystals of phenakite and dolomite could be recognized.
Siberian Pannas or more commonly known as Russian Panna is a development of thin, cavities parallel to the basal plane. Silvery luster by reflected light, but in some directions may appear black, due to total reflections. In Transvaal emeralds mica is usually a major inclusion, while in Indian Panna are found hexagonal cavities.
Pannas from the Ural mountains Siberian or Russian pannas have quite a different occurrence, and this is reflected in their inclusion. Flakes of mica may be seen often broken, but the most distinctive features are blades of green actinolite cracks across. Siberian Pannas is a development of thin, disc like cavities parallel to the basal plane. These show a silvery luster by reflected light, but in some directions may appear black, due total reflection.
The inclusions are mainly mica and liquid-filled cavities. At their best, the colour of these Pannas is said to resemble that of stones from Sandawana and Colombia.
This Gemstone of Lord Ganesha is the favored Gem of the people seeking intellectual powers as well as for those seeking wealth. This calms down the nervous system and improves the capacity to take right, calculated decisions. It improves the liquidity and money flow in business and blesses the wearer with cash, jewels, fixed deposits etc. Invariably wealthy people are seen possessing a lot of Pannas of different sizes and mines.
San Francisco chemist Carroll Chatham, are manufactured by a number of producers and by several different processes. The process used by Gilson, lennix, chathan, inamori and zerfass is the flus fusion method, involving crystallization of the beryl constituents from a melt in some suitable solvent such as lead molybdate. And then stone shows refractive indices birefringence, and SG markedly lower than those for natural emeralds and to have a stronger red appearance.