Lead Glass Treatments & Flux-Healing of Rubies
Surface cracks, cavities, or inclusions in ruby can be repaired using the "flux healing" (FH) method, also known as "glass in-filling.
Lead glass: A glass that contains a large proportion of lead oxide. The addition of this oxide raises the refractive index and makes it much more brilliant than ordinary glass. It was the most common glass imitation of diamond.
Lead glass imitation stone.
Pegmatites.....A very coarse platonic rock, generally granitic in composition. Usually forming dikes that cut granite or the gneisses and schists that border granite masses.
This was known as lead glass, and contained both lead and silica. Compared to soda glass, it was marvellously clear.
The subject matter was glass making, and in particular the lead glass used in Venetian enamels, glassware and imitation precious stones. This paved the way for the production of English lead crystal glass by George Ravenscroft.
Paste (lead glass) gives fairly vivid spectra, and they are single like those from diamond, as glass is singly refracting. The dispersion of the heavy lead glass approaches that of diamond.
Lead glass, such as lead crystal or flint glass, is more 'brilliant' because the increased refractive index causes noticeably more "sparkles", while boron may be added to change the thermal and electrical properties, as in Pyrex.
Lead crystal, also called crystal, is lead glass that has been hand or machine cut with facets. Lead oxide added to the molten glass gives lead crystal a much higher index of refraction than normal glass and much greater "sparkle".
Impregnated with colorless or colored lead glass filler to improve appearance; sometimes classified as composite gemstones, these rubies are treated using heat and a high refractive index lead-glass to fill fractures and cavities.
diamond substitute), Amethyst, Jade, Quartz, Topaz and Lapis Lazuli. When selecting a gemstone, some important factors to consider would be: a) The artificial materials used in the gem: Some artificial materials used include High-Lead glass, ...
Crystal
Crystal is a lead glass that has been hand or machine cut with facets. Lead oxide is added to molten glass to give lead crystal a much higher index of refraction than normal glass.
Today, generally means colorless potash-and-lead glass that contains quartz in the form of melted lead crystal and is cut like a diamond. Often backed with foil to enhance reflectivity. Also called strass, diamante.
Rhinestone Originally quartz from the gold washings along the Rhine river. Today, generally means colorless potash-and-lead glass that contains quartz in the form of melted lead crystal and is cut like a diamond. Also called strass, diamante.
The name comes from the Rhine river, which was the source of quartz crystals that were originally used in making rhinestones. Today rhinestones are made from cut lead glass and are usually foil backed to improve the reflective quality.
The originals were colourless quartz obtained from the River Rhine, which were cut in an attempt to resemble diamonds. The finest diamanté today is made of highly reflective lead glass, which is facetted and polished.
Color: surface reaching fissures may be treated with oil or dyes, resulting in stronger colours. Treatment not durable and requiring special care
Improving transparency: lead glass filling in cavities and fissures ...
Opal plates, which have been mounted on Onyx, Obsidian, artificial black glass, or Potch-Opal. Triplets have been developed from this design, here the Opal layer receives an additional cover from Rock Crystal, Plastic, Hard Glass or Lead Glass for ...
 See also: Lead, Glass, Stone, Surface, Rough
  
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