Basic Information on Crystal Cutting and Polishing

Rivoli detailMachine Cut
Preciosa benefits from more than a hundred-year-old tradition of the machine cutting of glass stones and beads. Unceasingly improved cutting and polishing technologies combined with the flawless optical properties of glass guarantee that every piece of crystal cut in Preciosa will display high brilliance, spark and decomposition of light into a rainbow spectrum.

Perfect Brilliance
Supreme crystal quality is reflected in its extraordinary optical properties. Like color hues, the cut of many shapes sought inspiration and model in genuine gemstones. As a result, color hues were named after gemstones such as topaz, sapphire, aquamarine, emerald, or garnet. The cut of shaped-back stones also borrowed terminology from the jewellery branch: brilliant, pear, navette, etc.
The similarity of crystal stones and genuine gemstones is sometimes so exact that only true experts can tell the difference. The same quality of cut is also observed in beads and pendants.

Categorization of Cut Stones:

Shaped-back Stones – Fashion Jewellery Stones
Like jewellery stones, these stones are set in metal or other materials. There are various setting technologies. Manual as well as machine processing is employed. 
Round Stones
Rhinestones (chatons) and rivoli are the most frequently applied stone shapes characterized with a round diameter. They come in a wide range of sizes that are determined in standard millimeters as well as in terms of a special size scale applicable to fashion jewellery stones and marked with the ‘ss’ (Stone Size) or ‘pp’ (Pearl Plate) symbols (please, see The Conversion Table of Sizes).
Fancy Stones
They represent a large segment of products. Frequently used are the following shapes: octagon, squares, navettes, baguettes, ovals and many others.

Flat-back Stones
Chaton roses and other flat-back stones are most often used for gluing and hot-fixing on a variety of base materials.

Stone Cutting Geometry

SBK shape MCCHATON43111111MC chaton (also chaton or rhinestone) is an essential and the most frequently applied stone in fashion jewellery. Its top surface contains 8 pentagonal facets and a central, regular octagon plate. The bottom part also consists of 8 facets whose position is slightly rotated towards the top facets and that taper together to form a tip. This design ensures extraordinary optical properties and has been tested by fashion jewellery producers’ many years of experience. The bottom part (it cannot be seen on a jewel) is used to set stones and is usually silver foiled - that pronouncedly enhances stone brilliance. The thin silver layer is protected with a top varnish film.
The sizes range from 0.8 mm (ss 000) up to 11.9 mm (ss 49). Chatons are available in a complete color scheme and with many types of refinement. Their applications are nearly universal.
Other stones, beads and pendants also have machine cut and polished facets. In case of stones, the facets may taper into a tip or can be ended off with one large facet; a so-called table.

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Basic information