Friday, December 31, 2021
Gemology Hub`: Natural Sapphire Inclusions There are several type...
Thursday, December 30, 2021
Optic fiber or fiber optic or man mand cat's glasses and their identification
Optic fiber or fiber optic or man made glasses come in a variety of different colors with a sharp cat's eye effect which imitat the natural gems for chrsoberly
Man made cat's eye glass |
when you see through the side view of the cabochons you will find hexagonal prismatic wax (honeycomb like pattern) as shown in the picutres below.
honeycomb-like pattern in optical fiber glass |
honeycomb-like pattern in optical fiber glass |
honeycomb-like pattern in optical fiber glass |
Requirement for a well-equipped gemological laboratory for analysing gemstones/diamonds
Establishment of well equipped Gemological laboratory For Gemstones / Diamond Testing Certification
1.
Natural Gemstones
samples e.g Emerald, ruby, sapphire (Cut/rough)
2.
Treated gemstones
samples (dyeing, filling, heat treated etc)
3.
Composite stones
(double/triplet)
4.
Synthetic gemstones
samples (made by all manufacturing process such as flux, flame fusion etc.)
5.
Natural diamonds
6.
Treated diamonds
(HPHT, glass or wax filling , irradiated etc)
7.
Synthetic
diamonds
8.
Diamond Imitation
stones (CZ, GGG) etc
9.
Master stones of
diamonds (For diamond color Grading)
10.
Energy dispersive
x-ray fluoresces (EDXRF), Positive
identification of rage gem material, separation of jade group, turquoise and
diamond from its simulants in parcels,
separation of natural from synthetic gems, origin determinations ,
identification cabochons and mounted stones.
11.
The Raman
Spectroscopy, gemstones and material
identification, identification of inclusions exposed at the surface and within
gem materials, separation of natural from synthetic material, separation of
amorphous and poly crystalline/ microcrystalline materials.
12.
X-Radiography, photographs of the internal structure of pearls and
other materials
13.
FTIR (Fourier Transmissions Infrared
Spectroscopy)
14.
Gemological
Microscope 45x but extendable to 120 x.
15.
Immersion
Microscope with attached Polaris filters.
16.
Refractometer
analog (sample) with liquid
17.
Refractometer
Digital
18.
Ultra Violet Lamp
with Short waves/long waves
19.
Spectroscope
20.
Specific gravity
Balance
21.
Specific gravity
liquids
22.
Polariscope
23.
Dichroscope
24.
Chelsea filter
25.
Loupe 10x
26.
Tweezers (sample,
lock, prong)
What is the definition of hardness? What is the Hardness Scale? How is it used in mineral testing?
Hardness Scale (Friedrich Mohs Scale)
Wednesday, December 29, 2021
Your diamond will be as unique as you are because of the inclusions.
You can claim your stolen diamond based on the inclusions.
Tuesday, December 28, 2021
Synthetic Diamonds: A Brief History
Synthetic Diamonds: A Brief History
In the early part of the twentieth century, several attempts to synthesise diamond were conducted, and by the 1940s, the temperature and pressure parameters under which diamond is the stable phase of carbon had been established experimentally. Berman and Simon expanded on these findings. Graphite is the stable phase at normal temperatures and pressures, which is interesting. At normal temperature and standard atmospheric pressure, diamond, the ultimate gemstone, is merely meta-stable! Fortunately, converting a diamond to graphite requires a lot of energy, and in an inert atmosphere, a diamond may be safely heated to at least 1500 °C without causing harm. When the temperature rises beyond 1800 °C, however, the material quickly transforms into graphite.
Following the availability of tungsten carbide in the 1930s, serious attempts to synthesise diamond started. This exceptionally strong material enabled the development of pressure cells capable of generating pressures of up to 400 000 atmospheres at ambient temperature and up to 70 000 atmospheres at high temperatures. Percy Bridgman of Harvard University conducted the first tests. No diamonds developed in any of the room-temperature graphite trials, and diamonds refused to form even when graphite was exposed to a pressure of 30 000 atmospheres and temperatures up to 3000 °C. Bridgman simply couldn't maintain high enough pressures and temperatures at the same time to convert graphite to diamond directly. Bridgman invented the expression "graphite is Nature's finest spring" as a result of these failures.
In 1953, a team of scientists at the Allmänna Svenska Elektriska Aktiebolaget (ASEA) laboratory in Stockholm solved the difficulty of turning graphite to diamond for the first time. That early achievement, however, was not acknowledged until after GE announced on February 15, 1955, that they had successfully turned graphite into diamond. In both situations, the secret to success was dissolving the graphite with molten metal. As additional graphite is dissolved, the metal gets saturated with carbon, resulting in the formation of tiny crystals that nucleate and develop. The crystals develop as diamonds because the temperature and pressure are kept at the zone where diamond is the stable phase. It's worth noting that the French chemist Frédéric-Henri Moissan attempted similar strategy 60 years before, but was unable to attain the circumstances where diamond is the stable phase of carbon.
However, it's almost probable that the GE scientists were thinking about Moissan's theories when they attempted, after several failures, to dissolve graphite in molten metal. It is still debatable whether the metal operates exclusively as a solvent or additionally as a catalyst, therefore the term "solvent-catalyst" is commonly employed. Cobalt, nickel, and iron are transition metals that function well as solvent catalysts, and these metals or alloys are employed in most commercial systems. In industrial synthesis, typical temperature and pressure values are 1400 °C and 55000 atmospheres, respectively.
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Required for the sign-up form (Please first read carefully.) Your name according to your CNIC card CNIC or POR card number. Email addres...
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Gemstone Quiz Submit
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A man brought a lot of the ruby from Afghanistan for certification. Synthetic ruby in the mother rock Most of the host rock (mother rock o...