Gemology Hub`: Natural Sapphire Inclusions There are several type...

Gemology Hub`: Natural Sapphire Inclusions There are several type...: Natural Sapphire Inclusions There are several types of inclusions in natural sapphires. • Needles. These are mineral inclusions that are lon...

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)

The bonds holding atoms together determine a mineral's

hardness.

In 1812, the Austrian mineralogist Friedrich Mohs devised a

scale of hardness that is still in use today. He selected ten

minerals as standards and arranged them so that any mineral on

 the scale 

would scratch only those below it. Everyday objects can be used 

to test where a mineral fits into the scale. A fingernail has a

hardness of 2.5, and a penknife is 5.5. Minerals of six and above 

will scratch glass; glass will scratch apatite and other minerals 

below it.

Mohs hardness scale 

The Mohs Scale of Hardness Explained

Your diamond will be as unique as you are because of the inclusions.

 You can claim your stolen diamond based on the inclusions.

Have you ever wondered why jewellers use special magnifying lenses to examine diamonds? They're looking for things to include. Inclusions, often known as faults, are internal characteristics of the stone that can only be seen when magnified. The size and kind of inclusions in a diamond determine its clarity.

Because imperfect diamonds are uncommon and expensive, the majority of loose stones, engagement rings, and other jewellery available includes some defect. An inclusion is similar to a freckle on your fiancé's nose; it's not a defect because it adds character to your diamond.

INCLUSIONS OF DIFFERENT KINDS

The majority of gemstones sold in jewellery stores are imperfect; they may have a variety of flaws. The following are the most prevalent forms of diamond inclusions:

Crystals 

Natural, uncooked minerals that form crystals are included within certain diamonds. This form of inclusion is often invisible to the human eye, but when enlarged, you may notice crystals in any hue of the rainbow depending on the mineral - charcoal (black), ruby (red), emerald (green), and so on. Colorless crystals are small diamonds encased within a cut diamond. Crystals created in certain forms or from unusual gemstones, such as your fiancé's birthstone, are actually regarded imperfections that add to the uniqueness and value of a diamond.

KNOTS AND NEEDLES

A needle is a crystal with a long, narrow shape because it was produced under extreme pressure. They are often white in colour, and bigger needles tend to detract from the beauty and value of the diamond.

A knot is formed when a crystal contacts the polished exterior of a diamond. These inclusions are more likely to be apparent without magnification since they are on the surface.

CLOUDS AND PINPOINTS

The most frequent type of inclusion is a pinpoint; when viewed via a loupe – a magnifying glass used by jewellers – they appear as white, grey, or black coloured dots. Pinpoints are microscopic crystals that, when found in groups, known as clouds, form a hazy region in the diamond and can lower its clarity grade.

FEATHER

Feathers are little cracks or spots inside a diamond where two surfaces do not quite contact. If the feather is not visible while the diamond is face up, it should have no effect on the clarity grade. Diamonds with huge feathers at the stone's perimeter, or girdle, should be avoided since they can make the stone less durable.

WISP TWINNING

This inclusion is essentially a collection of imperfections that emerged as the diamond matured, such as pinpoints, feathers, and crystals. Twinning wisps appear as streaks within the body of the rock and are twisted or twisting upon closer observation.

LINES OF GRAIN

Grain lines are minute cracks generated by changes in crystal development. They are often white or appear translucent and shiny. Grain lines are uneven crystallizations that, while they normally affect clarity, can reduce the strength of a gem if they are towards the edge.

GIRDLE FRINGE, BRUISE, AND LASER LINES

Girdle fringe (also known as bearding), bruises, and laser lines are examples of unnatural inclusions that occur when the stone is cut or polished. Girdle fringe is made up of thin, hair-like lines that run down the diamond's edge and can typically be removed with polishing. Bruises are dents in the crown of the diamond caused by the polishing wheel. Laser lines resemble steam trails that stretch from the diamond's surface into the core, where laser drilling was employed to remove dark crystal defects.

Diamond professionals strive to improve the purity of the diamond and guarantee that it sparkles as much as possible, but these types of inclusions are occasionally the outcome of their labour. Trustworthy jewellers will notify you if a stone has been boosted in any manner, but these sorts of inclusions should not reduce a diamond's longevity.

CHIPS

Flaws on the diamond's surface, most commonly visible on the girdle, indicate that it has been injured and its structure has been compromised. Though little nicks may be cleaned or buffed away, the diamond may chip again in the future. Larger chips would necessitate re-cutting to preserve the diamond, but this obviously diminishes the overall size of the stone.

Ring and jewellery settings can conceal flaws, which is why it's critical to have the diamond removed before carefully scrutinising with a loupe. You may even run your finger over its surface to check for flaws. Chips should be avoided when purchasing antique or vintage jewellery since they can be caused by regular wear and tear.

CRACKS

Inside a diamond, lines without feathering are fractures, and they are a major fault in terms of a stone's value and integrity. Cracks make the gem more vulnerable to force and increase the likelihood of it splitting completely. It is preferable not to buy diamonds with long fractures that touch the surface.

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.

Petroleum Quartz

Petroleum Quartz (Quartz with Petroleum, Methane, Bitumen, and Water)

Being a particular kind of enhydro , doubly terminated quartz crystals containing negative crystals filled with petroleum, methane, bitumen, and water, are rare, though material of very good quality appears on gem and mineral fairs on a regular basis. Under ultra-violet radiation the petroleum inclusions present in the material reveal a strong fluorescent reaction.

This most striking material originates from the Zhob District in Balochistan Province, Pakistan, although some time ago one dealer had material on offer unearthed in the Jihouke District, Leshan Prefecture, Sichuan Province, China. However, these samples contained quite some bituminous matter, but far less petroleum and resemble herkimers with anthraxolite from the Adirondack Mountains in New York.

It might be interesting to note that petroleum inclusions similar to those in Pakistani quartz have also been found in quartz crystals originating from Bahia, Brazil (Gübelin & Koivula, 2005).

Petroleum Quartz from Baluchistan, Pakistan 

Petroleum Quartz from Baluchistan, Pakistan 

Petroleum Quartz from Baluchistan, Pakistan 

Petroleum Quartz from Baluchistan, Pakistan 

Petroleum Quartz from Baluchistan, Pakistan 

Petroleum Quartz from Baluchistan, Pakistan 

Petroleum Quartz from Baluchistan, Pakistan 

Petroleum Quartz from Baluchistan, Pakistan 

Petroleum Quartz from Baluchistan, Pakistan 

Petroleum Quartz from Baluchistan, Pakistan 

Petroleum Quartz from Baluchistan, Pakistan 

Petroleum Quartz from Baluchistan, Pakistan 

Petroleum Quartz from Baluchistan, Pakistan 

Agate World

The page is devoted only for beautiful agate and agate lover all over the world.

Agates collection 

Agate from China

Agate from Pujiang, China.

Agate from Pujiang, China.

Agate from Pujiang, China.

Agate from Pujiang, China

When almus agate is cut, many plumes and usually yellow and red bands appear.

Almus Agate

Turkish produces beautiful agates

Turkish Agate

Turkish Agate

Turkish Agate

Black sea agate North Turkey

Black sea agate North Turkey

Black River Agate

This is a 3.25 inch stream rolled agate which was cut in half and polished. It is from Argentina and is called a Black River Agate. I acquired it back in 2008.

Black River Agate

Bobonong, Botswana

Bobonong, Botswana

Amazing Diamond Twin

حیرت انگیز ڈائمنڈ ٹوئن

دو ہیرے کے کرسٹل جو جڑواں میکل ہیں اور نایاب ہیروں  غور کرتے ہیں۔ دو فلیٹ مثلثی کرسٹل (جسے میکلز کہتے ہیں) ایک ستارے کی شکل بنانے کے لیے بالکل صحیح زاویہ پر اکٹھے بڑھے۔

بائیں جانب جڑواں ہیرے کے کرسٹل کا وزن 0.92 کیرٹ اور دائیں جانب والے کا وزن 0.97 کیرٹ ہے۔

Rare Twinned Diamonds 

تصویر: رابرٹ ویلڈن/جی آئی اے۔ بشکریہ: مارون فنکر، ٹریلین ڈائمنڈز۔

Bumblebee Jasper

Honey bee Jasper is a deceptive name of calcite (calcium cabonate) with considerations of arsenic and manganese oxides with banding and layering which is looks like a honey bee that why it called honey bee Jasper.

 

The inclusions caused by sulfur (yellow), calcium & Aragonite (white), Orpiment & Realgar (orange), and Pyrite (black).

bumblebee Jasper (Calcite)

This mineral was only discovered in the 1990’s  west Java Province, Papandayan Volcano, Indonesia. Since then, this mineral has yet to be discovered anywhere else on Earth and geologists don’t expect to find another deposit of it anytime soon. This is an extremely rare occurrence in nature that simply doesn’t happen and it should be cherished, respected, and valued for the true uniqueness it holds.

The Dichroscope, it types, its construction and its uses

T

he dichroscope is a pocket-sized tool that can aid in the identification of gemstones. This tool is used to inspect pleochroism (leochroism is the change of color in colored anisotropic double refractive  gemstones when viewed from different directions) in gemstones and to quickly separate some common stones from each other (such as ruby versus red garnet).

Basic

There are two types of dichroscopes on the market:

• calcite dichroscopes
• polarizing dichroscopes

In anisotropic gemstones, different colors are absorbed in different directions ("directional selective absorption") which causes the pleochroism that is observed with the dichroscope.

Calcite dichroscope

The calcite dichroscope is the preferred type of dichroscope used in gemology. It works because the calcite rhomb (Iceland spar) separates the polarized slow and fast ray emerging from the gemstone. If you look at the viewing end of the dichroscope, two small windows are seen.
A gemstone is placed in front of the aperture (slightly touching it) with a strong white light source (such as a penlight) directly behind the stone. Light enters through the aperture of the dichroscope. The pleochroism colors inside the gemstone are separated by the calcite rhomb. The glass prisms on either side of the rhomb are there to guide the light straight through the instrument.

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Calcite dichroscope

Calcite Dichroscope 

Calcite Dichroscope 

view in calcite dichrosoope 

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Polarization dichroscope

Two polarizers

Pleochroism may also be observed with the use of a polarizing filter. The disadvantage is that one will only see one of the pleochroic colors at a time, making subtle changes of colors (shades) difficult to recognize. This can be overcome by placing two polarizing filters close together, each orientated 90° to the other (one in North-South and the other in East-West position).

Although this kind of dichroscope is very economical, the results obtained by them are less clear than in the calcite ones. Stones with weak pleochroism will be hard to determine with this type of tool.

The London dichroscope is a popular brand.

Polarization dichroscope

pleochroism in polarization dichroscope

pleochroic stone in london dichroscope 

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Proper use and possible observations

Inspection directions

1. through the table
2. through the crown facets
3. another direction through the crown facets
4. through the girdle
5. a different direction through the girdle

There are three possibilities to test the gemstone in Dichroscope

1. the colors in both windows remain the same in all directions

the stone is isotropic (single refractive)

2. in total 2 colors are observed  

the stone is anisotropic uniaxial

3. in total 3 colors are seen

the stone is anisotropic biaxial

Pleochroism in different gemstones