Inorganic Gemstones

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SEM

SEM is highly sophisticated equipment and only a few gemmological laboratories in the world have access to it. This technique is surface oriented and provides a very high magnification of the surface topography. With additional attachments, elemental analysis can be obtained.

  • The basic features include a fine stream of electrons which are focused at a particular angle on the specimen which is scanned in a series of parallel lines.
  • In this technique, secondary electrons are emitted from the specimen due to collision with the high energy incident beam.
  • High energy backscattered electrons are emitted. These are electrons from the incident rays which have interacted with the specimen and then reflected out.
  • The intensity of both emissions is collected, and converted with compatible software to a visible image.
  • Polished specimens give a better result, since in rough specimens the variations are due to surface rather than the actual structure.
  • In most cases the samples have to be coated with a layer of silver or gold for more accurate results.
  • This is useful in the identification of gemstones, their origin and treatments such as the glass fillings in ruby (since ruby fluorescence masks these peaks in all the other mentioned techniques).

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In Germany, the garland of ambers is hung around the necks of the infants, so that their teeth might come out without much trouble.

In Turkey, people fix a piece of amber in the hubble-bubble, dogged by an age old belief that the presence of the jewel would destroy all the germs and no disease would spread, even after many have dragged their puffs from it.

In Greece, people think if wine is poured into the cups made of amethyst, one does not get drunk after drinking that.

In Rome, a talisman having coral pieces is considered very auspicious to quell the bad spells of evil look. The Romans were in the habit of hanging chains made of ancient coral pieces from the cradle of the infants to protect them from evil effects.

In China, people wear rings studded with tiny conch or oyster shells as they believe it cures all aches such as stomach ache, worms and like.

In India, pendants made of silver and studded with pearls are hung from the necks of the children to save them from any bad effects.

Greeks still believe, if women wear blue sapphires then no sense of immorality would pollute their mind nor can any fear of the supernatural can trouble them.

The Pope Innocent III had circulated an order asking all the priests wear blue sapphire, so that morality can be strengthened.

It is said about turquoise, that when the stone changes its color into yellow, it actually signals bad times to the person who wears it.

It is believed that a turquoise gifted to a friend or a lover turns his or her life into one of happiness and good luck.

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