Inorganic Gemstones

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Flux Fusion

This method was developed only in the late 1930's and has since been perfected to a great extent.

  • A flux is a material that lowers the melting point of a substance with which it is mixed.
  • Some materials are quite insoluble in high temperature water, but are soluble in a flux.
  • The common fluxes used are lead fluoride, lithium molybdate and boron oxide.
  • Flux materials have fairly toxic fumes and are also very reactive materials.

How gemstones are synthesized by flux fusion process?

  • In most cases the crucibles are made of platinum, but iridium and graphite are also used.
  • Powdered ingredients are mixed with the flux in a platinum crucible.
  • On heating, the flux melts and becomes a powerful solvent for the other ingredients which also melts.
  • Cooling and evaporation causes crystallization of the molten material with or without the use of seed crystals.
  • As the growth is slow and equipment costs are high, these synthetics are expensive when compared with those by the methods discussed earlier.

Gemstones synthesized by flux fusion with its identification.

  • Synthetic Emerald:
    • The characteristic inclusions seen are flux fingerprints in the form veils and droplets or globules, hexagonal and / or triangular platelets, parallel growth structures or venetian blind effect, seed plate, spicules and included crystals.
    • Earlier flux emeralds have a lower R.I. = 1.56 - 1.565, D.R. 0.005. Recently available flux emeralds tend to have similar R.I.'s as the natural counterparts.
    • Earlier flux emeralds have a lower S.G. = 2.66. Recently available flux emeralds tend to have similar S.G.'s as the natural counterparts.
    • Flux emerald with high chromium content exhibit a strong red transmission to light, appear strong red through the Chelsea filter, and appear strong red under ultra violet light.
    • A few of the well known producers of these emerald are P. Gilson (France), G.F. Chatham (U.S.A), Zerfass, Lennix, Seiko and Russia.
  • Synthetic Corundum (Synthetic Ruby / Synthetic Sapphire):
    • Synthetic corundum has similar physical and optical properties as the natural counterparts.
    • Under magnification - flux fingerprints in the form veils and droplets or globules, flux droplets maybe whitish or orange (Ramaura) in colour, hexagonal and / or triangular platelets, parallel growth structures, zoning characterised by process, seed plate, spicules and included crystals.
    • A few of the well known producers of these rubies are Kashan (U.S.A), Chatham, \/ocera (Japan), Lechleitner (Austria), Ramaura, Knischka, Duoros (Greece), Tairus, Russia etc.
  • Synthetic Spinel:
    • Synthetic spinel has similar physical and optical properties as the natural counterparts.
    • Synthesized in red and recently blue varieties.
    • Under magnification flux droplets and veil like flux fingerprints are seen.
  • Y.A.G.:
    • Colourless when pure (without any dopants) - diamond simulant.
    • Isotropic character.
    • The S.G. is 4.55 - 4.60
    • Dispersion - 0.028
    • Flux veils under magnification.
  • Synthetic Chrysoberyl:
    • Synthetic chrysoberyl has similar physical and optical properties as the natural counterparts.
    • Synthetic alexandrite and synthetic chrysoberyl cat's eye have been synthesized.
    • Flux fingerprints, fine dust like pinpoint inclusions and droplets are seen under magnification.
    • Synthesized by Creative Crystals, Ramaura, Seiko, Kyocera (Inamori), Russia.

Did you know?

Jewellery is one of the most bought products online. An estimated $1 billion USD of diamonds are bought annually via the Internet. Over 40 million people use the Internet to trade!

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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