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| Calcedonio
Glass |
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Calcedonio (Italian, "chalcedony")
Glass marbled with brown, blue, green, and yellow swirls
in imitation of calcedonio. Fabricated in Venice around
the year 1500 and later in 1700. In the XVII and XVIII
centuries a marbeled red glass was fabricated in Bohemia.
It was used again in the second half of the XIX century. |
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| Calcedony |
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A translucent to transparent milky or grayish
quartz with distinctive microscopic crystals arranged
in slender fibers in parallel bands.
its main varieties are: agate, carnelian and chrysoprase.. |
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| Calcite |
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(Ca) Chemical element from the alkali-earth
family.
It is one of the most abundant element on earth’s
crust, mainly found as carbonate (calcite and limestone),
sulphate (chalk), fluoride (fluorite), and phosphate. |
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| Calcium |
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With lime content. Sedimentary rocks primarily
made up of calcium and magnesium carbonates.
Contains calcium carbonate (Ca CO3). |
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| Cameo engraving |
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Engraving with low relief to show the design
and background in contrasting colours. This type of work
required the use of a machine runned by water. This technique
was known in Egypt and was used to brand seals and in
gem cutting.
Cameo glass Overlay acid-etched in cameo style in England
at the end of the XIX century. Glass of one layer covered
usually by casing with one or more layers of contrasting
color(s).
The outer layers are acid-etched, carved, cut, or engraved
to produce a design that stands out from the background.
The first cameo glasses were made by the ancient Romans.
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| Casing |
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Glassware made by two or more layers of
different colours. A technique whereby glass of one colour
is fused onto the inner surface of glass of a different
colour, using a performed ‘cup’ of one colour
and introducing into it a glass of a different colour.
By repetition, a multicoloured layered glass can be produced. |
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| Ceramics |
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Clay craftsmanship. The art of elaborating
earthenware and other clay items, tableware and porcelain.
Considered as scientific knowledge from an archeological
point of view. |
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| Clay |
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Clay, a natural, earthy, fine-grained material
occurring naturally from the weathering of rocks, thus,
with no specific chemical formula. Clays are fine grained,
generally in the size range of less than 0.004 mm (0.00015
in), with most grains less than half this size. If the
grains are larger in size it is called slime.
The clay minerals are hydrous silicate minerals, some
of them with magnesium or iron replacing aluminum totally
or partially, alkali and alkaline earth compounds, as
well, always made up of fine grained particles.
Clay minerals occur naturally from the weathering of rocks
and are components of argillaceous deposits, bentonite,
industrial vermiculite, etc.
All of them belong to the phyllosilicate mineral group,
clustering according to the stratus nature and the manner
it compounds to the structure. Its properties are linked
to the structural scheme of each group.
Clay is a fine-grained rock that, when adequately grinded
or powdered, becomes plastic when dampened and acquires
the consistency of hide when dry, when fired becomes a
permanent rocky mass. (American Ceramic Society).
Clay is the resulting product of earth’s aging process.
Material of natural origin, occurring naturally from the
weathering of rocks. Clay has no specific formula and
all existing types are a mixture of minerals with a high
share of ‘clay minerals’ such as kaolinite. |
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| Cobalt Glass |
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Blue coloured glass obtained by the use
of cobalt oxide. Europe main cobalt deposit is found in
the Metalliferous mountains. In Venice, glassmakers started
using cobalt in the XV century. |
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| Cristallo |
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Cristallo (italian).
A type of soda glass developed in Venice, perhaps before
the XV century. |
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| Crizzling |
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Chemical deterioration of glass due to
the effects of moisture.
Solid crystal mineral which atoms or molecules have a
definite, orderly atomic structure and an outward form
bounded by smooth, plane surfaces, symmetrically arranged.
Crystallized variety of colorless, transparent quartz
used as precious stone and in the fabrication of optical
and electronic instruments. |
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| Cutting (graving) |
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Process of cutting into glass surface by
the use of a rotating wheel of iron or stone of different
shapes and sizes. Using an abrasive material (damp sand,
emery) between big wheels rotating horizontally faceting
can be obtained. Small wheels of different shapes rotating
vertically are used to cut motifs. The shape of the wheels
can be flat, convex, or mitered. This technique was taken
from stone cutting techniques from ancient times. |
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| Cylinder glass |
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Same as Broad Glass. Flat pane Glass made
by the process of blowing a large glass bubble and swinging
it on the blow pipe to form a long bottle and cutting
off both hemispherical ends. |
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