Universities

Charles T Munger, Vice-Chairman of Berkshire Hathaway Corporation writes:

'There's a lot wrong (with American universities). I'd remove 3/4 of the faculty -- everything but the hard sciences. But nobody's going to do that, so we'll have to live with the defects. It's amazing how wrongheaded [the teaching is]. There is fatal disconnectedness. You have these squirrelly people in each department who don't see the big picture.'

Burmite

Garry Platt writes:

Burma up until recent years had been China’s major source of amber. The Burmese had mined and dug for the amber which was then sold to Chinese traders who would sell on to crafts people who prized the gem for its qualities and mythical properties.

The amber was extracted from the Northern parts of the country. The mining shafts were lined with bamboo canes sunk down 10 -15 meters through clay deposits. ‘The Mineral Resources of Burma’ published in 1934 noted 200 pits aimed at extracting amber near the village of Shingban. Photographs from this period show these mines as potential death traps. The author is uninformed about the situation regarding amber mining within this region at the current time. Most records refer to activity up until the 1930’s, but none later. The age of Burmite has been established as Eocene through indicator fossils present in the amber deposits. The tree origin has been determined as Nummulites Biaritzensis.

More info @ http://www.gplatt.demon.co.uk/typesof.htm

Diamond Cut: CRISSCUT

The step cut Crisscut has 77 facets, some of which are crisscrossed, and comes in two shapes:

-Rectangular
-Octagonal.

Triangular facets are applied to the steps in the pavilion. Crisscut is the creation of Christopher Slowinski, the owner of Christopher Designs.

How To Judge Asterism

Asterism may be perceived as multiple chatoyancy.

The Star
- Is it sharp and intense?
- The star should be complete with no missing or weak rays.
- The star itself should roll or travel easily across the surface.
- The intersecting rays should meet as near as possible at the center of the stone. If the stone is cut so that one
of the arms of the star cuts across the shortest axis of the cabochon; the rays are evenly spaced and pleasing
to the eye. In the gem trade, this is described as "Open Star". If a ray is oriented across the longest axis of an
oval stone, then the rays will appear to be less pleasing to the eye. This is described as "Closer Star".

Body Color
- Does the stone have a good body color?

Clarity
- The stone should be free from cracks and fissures. Surface reaching cracks and fissures are undesirable
forming traps for dirt, weakening the stone.

Transparency
- There is a very fine balance between transparency of the stone and definition and intensity of the star. Too
much silk or inclusions will induce translucent or even opaque body color, while too little silk or inclusions
may create ill-defined star.

Cutting
- Is the cabochon shape pleasing to the eye?
- A fairly high dome is necessary to focus the star to the best advantage. This is because the dome of the
cabochon acts as a condensing lens to concentrate the rays of the star. If the dome of the cabochon is cut
as shallow curve it is liable to possess a nearly flat spot at the top producing diffused star that will almost
invisible unless the observer is directly above the stone. A well-proportioned dome with a smooth and even
curve, lacking any flat spots, should produce a sharp star visible from most angles.
- The weight below the girdle should not exceed approximately 20% of the weight of the stone. Most colored
stones are purchased by weight so excess material beneath the girdle that does not contribute to the body
color or to the star is an unnecessary expense. Some native cut stones are practically spherical. Such stones
should be valued at the weight they would be if cut to correct proportions.
- In highly transparent gemstones a concave base can be a decided advantage as it will provide greater
brilliance, although it should not contribute to the weight excessively. Ideally the back of a translucent or
near opaque stone should be flat, smooth, but unpolished. If the gem is sufficiently transparent it will show
any polishing defects such as pits or cracks on the base.
- Test the symmetry by spinning the stone on a flat surface. If the stone wobbles or the star is seen to oscillate,
this indicates an unsymmetrical stone. Also look out for any chips or nicks at the girdle.
- The surface polish should be good with no pits, nicks or pieces of matrix to disturb the movement of the star.

Microscope

What Are The Primary Functions Of Microscope?

The primary function of microscope is to enlarge the image under view in order to help differentiate between natural and synthetic. Inclusions can indicate not only whether a material is natural or man-made, but also help identify the geographic origin of natural stones as well as the method of formation of those produced in a laboratory.

Natural: crystal, liquid and gaseous inclusions, or a combination of the aforementioned (e.g., two-phase (liquid + gas), three phase (mineral + liquid + gas), negative inclusions, straight color zoning, oriented silk (chatoyancy and asterism).

Man-made (synthetics and artificial stones): inclusions due to growth conditions which are for the most part dissimilar to those found in natural material. For example:
- Melt synthetics (flame fusion, pulling method, floating zone): curved color zoning; unmelted particles, gas bubbles like tadpole, dumb bell in shape or circular bomb-like, are common, but new specimens may be relatively clean.
- Solution synthetics (flux): primary and secondary flux inclusions, platinum platelets, twisted veils, phenakite crystals (emerald); paint splash-like, mesh-like flux, platinum platelets (corundum); (hydrothermal) nail-like, cuneate forms (phenakite crystal and growth tube), growth zoning patterns (chevron-like, wheat stalk-like) liquid and multiple phase inclusions in wispy or fingerprint patterns, metallic inclusions in the form of gold platelets or grains from gold-lined autoclaves or platinum crystals, seed crystals, if any.

Paste: air bubbles, swirl marks, incomplete color mix. Specialty glasses like aventurine glass, slocum stone, rhinestone, foilbacks,etc.,

Assembled (composite) stones (doublets + triplets): squashed bubbles in plane of join, difference in color, inclusions, luster in various sections.

Pearls (cultured and imitation): filled glass bead or coated bead (imitation), drill hole discontinuity layer.

Artificial treatment: heat treatment—strain halos around inclusions, double girdle (polished and fireskin sections: corundum); surface diffusion— revealed by immersion, dark rim, bleeding of color into pits, uneven color due to reploshing (magnification not essential: corundum); fracture filling—dispersion flashes, gas bubbles, color of the compound (emerald); glass filling—difference in luster, gas bubbles (corundum); beryllium treatment—color spots, cottony-like crystals, color rim, melted crystals; lead glass filling—dispersion flashes, melted crystals, color irregularities (corundum, diamond); staining—color build up in cracks and flaws; Irradiation—irradiation stains, cyclotron umbrella-like color in diamond, etc.,

General observations: The observation of external gem features such as luster, quality of cut (symmetry) and polish (condition of facets), detection of breakage (fracture and cleavage) or gem vulnerability to damage, detection of doubling in double refractive stones (indicating the amount of birefringence).

The microscope may be further adapted in conjunction with additional equipment to carry out the following functions:

Polariscope: with the aid of two suitably placed Polaroid sheets—SR/ADR and DR/Aggregate reactions may be noted. Interference figures—a convergent beam of polarized light along an optic axis may produce figures indicating uniaxial or biaxial nature of a DR stone. In addition, the optic sign may be deducted from these figures using accessory plates (e.g., mica plate or quartz wedge).

Pleochroism: using one polar (or two polars side by side with the vibration directions at right angles to one another) while the stone is rotated; it may be possible to note differences in color.

Refractive index: accurate and/or approximate R.I may be determined by the following methods. Real & Apparent Depth Method (R.I = real depth / apparent depth); Immersion Contrast; Becke Line Effect (simplified Becke).

Spectroscope: by fixing a spectroscope in place of an eye piece and observe absorption and emission patterns.

Plato Method: for distinguishing between pale colored natural and flame fusion synthetic corundum when characteristic inclusions are not noticeable (in di-iodomethane—methylene iodide), view along optic axis through crossed polars at 30x, dark lines intersecting at 60º indicate synthetic; in most cases, natural stones won’t show lines.

Photomicrography: fix camera adapter in place of an eye piece to record inclusions for further study or reference.

Other: measurement of stone using calibrated stage; measurement of interfacial angles using rotating stage.

Diamond Cut: BAROCUT

The Barocut is considered rectangular modified cut with 77 facets-81 in cut corner style. The cut is also perceived as "The Two Heart Diamond" due to the look of two hearts meeting point to point deep into the culet of the diamond.

The Barocut diamond brand is the creation of Baroka Creations Inc.

Chemawinite

Garry Platt writes:

Amber from the Cretaceous is rare, but Canada has some remarkable deposits originating from this age. Cedar Lake in Manitoba is probably one of the most commonly written about sites. The Cedar Lake deposits were found on the South West lakeside shore as washed and tiny pieces ranging from .5cm to 2cm in diameter. Highly fossiliferous by all accounts containing many examples of both flora and fauna.

Various scientific expeditions have brought back several hundred pounds of amber from this site. In the 1950’s a project was set in place to begin commercial development of the site. The venture later failed. This site has now been lost to science because of the flooding of the area. The former lake side shore is now hidden beneath the new water level. Reports have been made of amber beginning to appear on the new higher shoreline. So far these reports have been unsubstantiated.

More info @ http://www.gplatt.demon.co.uk/typesof.htm

How The Spectroscope Works

The spectroscope splits visible light into its component colors (using either a set of prisms, or in the less expensive models, a diffraction grating) producing essentially the colors of the rainbow--red, orange, yellow, green, blue and violet. A diffraction grating spectroscope achieves this by using a finely ruled grating consisting of a series of photographically etched parallel lines (as many as 1000 per millimeter) on a sheet of glass. This produces a series of spectra by diffraction and interference, but only the strongest spectrum is used. For proper viewing of gemstone spectra a concentrated light source is required.

Lighting and Use
With an adjustable slit spectroscope, resist the temptation to open the slit wider than it necessary as it only tends to make matters worse by drowning the spectrum with too much light. Instead, try moving the stone to let more light through it, or use a lens to further concetrate light into the stone.

The difficulty in reading lines, bands or absorption in the blue violet end of the spectrum can be overcome, in some instances, by filtering the incident white light through a flask containing a solution of copper sulphate and distilled water (copper sulphate is toxic, so care is necessary when handling it). By filtering out the distracting longer wavelengths (red, orange, yellow, etc) the eyes adjust more readily to the subtle differences seen in the blue violet end.

Inability to see a spectrum may be due to the fact that only a small trace of the spectrum causing agent is present, or that insufficient light is reaching the spectroscope for analysis (e.g , in very dark stones or semi-translucent to opaque material). In very pale or shallow stones, try passing the light through the maximum amount of material in order to enhance the strength of the absorption pattern seen.

Keep in mind
Not every stone has a spectrum, and not every spectrum you see is helpful in gem identification. More important--don't expect all spectra to look as neat and tidy as those illustrated in books. In stones with different selective absorption (dichroic or trichroic) the spectrum may vary depending upon the direction in which the stone is viewed. Spectrum analysis is only one test leading to positive identification of a stone.

How To Judge Chatoyant Stones

There are many gemstones that can show chatoyant phenomena, but the cat’s eye of a fine chrysoberyl combined with the stone’s excellent hardness and durability designate it as the precious cat’s eye among gems.

In the trade, the term cat’s eye alone will always refer to chrysoberyl unless another species is mentioned as a qualifier such as quartz cat’s eye, tourmaline cat’s eye, diopside cat’s eye, kornerupine cat’s eye, etc.

Chatoyancy is a reflection effect from oriented parallel fibrous inclusions or cavities. Light reflects off these needles and if the stone is cut correctly, this results in a single sharp band of light running across the top of the stone similar to a cat’s eye. The domed surface of the cabochon acts like a lens to focus the eye. The grading of phenomenal stones involves the judging of the phenomenon itself as well as the other components that make up the accurate grading of a gemstone.

There are five factors to consider when judging the quality of a cat’s eye.

- The cat’s eye itself

Is it sharp and intense? Is it wavy or even and well-centered? Does it extend from girdle to girdle, and is it properly orientated? Does the eye run lengthwise? Does it open and close?

- Does the stone have good body color?

Is the body color desirable?

- Does the stone have good transparency?

Is there good transparency without sacrificing the sharpness of the eye? There is a very delicate balance in maintaining transparency, yet not being so transparent that the sharpness of the eye is weakened. The base of highly transparent cabochons is often left unpolished for this very reason.

- Does the stone have good clarity?

Are there imperfections, internal or on the surface that interfere with the eye? Do the imperfections distract the viewer from the eye, or decrease the transparency of the stone?

- Is the cutting good?

Is the cabochon shape pleasing to the eye? Are you paying for excessive weight below the girdle that will not be visible when viewed face-up?

Fracture, Cleavage, Parting

1. What is fracture?
Fracture is an uneven break in a gemstone.

2. What is cleavage?
Cleavage is an uneven break parallel to a crystal face due to weakness in molecular bonding.

3. What is parting?
Parting is a breakage due to structural weakness either caused by inclusions or areas of twinning.

Toughness

1. What is toughness?
Tenacity is defined as toughness. By definition it is a measure of resistance of a gem to breaking or fracturing.

2.What is the relation of hardness and tenacity?
They are not related. Hard stones are not necessarily tough. Diamond, the hardest, cleave while nephrite, which is not hard, is very tough.

Hardness

1. What is hardness?
Hardness is defined as resistance to scratching.

2. What scale do we use to judge it?
The Moh's scale.

3. List the order of increasing hardness on the scale with an example at each level.
Talc(1), gypsum(2), calcite(3), fluorite(4), apatite(5), orthoclase(6), quartz(7), topaz(8), corundum(9), diamond(10).

4. What is considered to be the minimum acceptable hardness for a gemstone?
7. Stones with a hardness less than 7 will scratch more easily so how they are fashioned into jewelry and how they are cared for is important.

Shape and Cutting Style

How to distinguish between shape and cutting style?

Shape is simply the way the girdle is cut ie., round, square, oval etc., while cutting style is how facets are cut on the crown and pavilion.

Tweezer

What are the characteristics of a good tweezer?

A good tweezer should be dull, with non-reflective surface and good spring, with inner groove near tip.

Antique Cut

An antique cut is defined as square or rectangle shape with corners rounded.

Colored Stone and Light Source

Which light source is used to distinguish color? Which light source is used to judge transparency?

To distinguish color use reflected light.

To distinguish transparency use transmitted light.

Natural Stone, Enhanced and Synthetic Stone

What is the difference between a natural stone, enhanced and a synthetic stone?

Natural: as found in nature with only cutting and polishing done. Ex. Natural, ruby, sapphire, emerald, garnet.

Enhanced: a stone that has been treated by man such as heating, oiling etc.,. Ex. Treated rubies, sapphires, emerald.

Synthetic: man made stone which has a counterpart in nature and has the same chemical, physical and optical properties as the natural stone. Ex. Synthetic ruby, sapphire, emerald, diamond.

How To Become A Good Investor

Charles T Munger, Vice-Chairman of Berkshire Hathaway Corporation writes:

'If you're going to be an investor, you're going to make some investments where you don't have all the experience you need. But if you keep trying to get a little better over time, you'll start to make investments that are virtually certain to have a good outcome. The keys are discipline, hard work, and practice. It's like playing golf -- you have to work on it.'

Dominican Republic Amber

Garry Platt writes:

Dominican Republic amber, probably the world’s second largest deposit following that of the Baltic amber region, strangely does not have a unique name but can be called amber because of the presence of Succinic acid though not to the same level as Baltic amber. It is commonly referred to as Dominican Republic amber. Throughout the island are numerous mines which tap into different deposits of amber. Laid down in successive layers the age of the amber extracted can vary from between 15 - 40 million years. The tree origin has been established by Poinar as Hymenaea protera.

More info @ http://www.gplatt.demon.co.uk/typesof.htm

Dubai Cut

National Jeweler Network writes:

Dhamani Jewels DMCC, the sole distributor of the "Dubai Cut" diamond, has announced the launch of a jewelry line incorporating the gems and inspired by the shape of the letter "D."

Unveiled as the world's first diamond cut inspired by and named after a city, the 99-faceted Dubai Cut reflects the 99 holy names of Allah. Russian polished-diamond manufacturer Kristall Corp. produces the unique cut exclusively for DMCC under a legal patent.


More info @ http://www.nationaljewelernetwork.com/njn/content_display/diamonds/e3i73449c66171eef175fcbbfd77ca40240