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Portraits
- Antique Copies 
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 Smalti
is hand-made glass
mosaic tiles, either transparent or opaque. It is produced by the melting at a very high
temperature and the cooling of a mixture of silica (vitrifier), consisting of sand,
calcium oxide (stabilizer), sodium or potassium oxide (fluxes). Metal oxides such as
opacifying and coloring agents may be added to this basic vitreous mixture.
Smalti is the same material used in the ancient Byzantine and Roman mosaics.
Sometimes tiny air bubbles are visible: this is not a defect, on the contrary, it means
that it's a high quality product.
Smalti are available in circular discs named "pizza" approximately 1-2 cm.
(0.40"-0.80") thick and 15-30 cm. (6"-12") in
diameter
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| 3-Dimensional
Mosaics |
 The difference
of
Smalti is the chemical composition. Vitreous pastes do not contain lead oxide and are
therefore slightly opaque and hard to cut. Furthermore, they are not shiny like smalti.
They are usually available in squar pieces (0.40" x 0.40" or 0.80" x
0.80" or 2" x 2" ) |
| Mosaic
Tables, Micromosaic |
There is a
special type of
smalti used for the manufacture of micromosiacs, a technique mostly adopted in
Roman & Vatican Workshops.
This technique was invented by Giacomo Raffaelli in 1780 and consists of
melting some pieces of master tints in a crucible over an open flame.
When the glass is molten, it is drawn into long thread-like rods by means of
tweezers. The
"filato" rods are then allowed to cool and clipped into tiny pieces even smaller
than 0.05" |
| More
applications.. |
It is used as a decorative
building stone, because it can easily be worked and cut into tesserae.
A wide variety of colors are available in marble : from black, yellow and brown to green,
red and pink, depending on the presence of various minerals - e.g. white marbles are
composed of pure calcium carbonate . |
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