16/09/2011

The history of gemstone carving

The terms intaglio and cameo are defined as carved gems with incised and raised engraving, respectively. The carving may be done either by simple manual tools or by rotary tools ( drilling and grinding ). The material for engraved gems is chiefly yielded by the minerals of the quartz group. Hematite was used for the ancient mid-eastern seal-cylinders. Engravings on emerald, beryl, garnet, peridot and topaz were rare. Through all ages glass offered a material for imitating, and substituting gems. For these glass-pastes a mold of an intaglio or a cameo was pressed in clay to cast the glass, which, after cooling, was brought into its final shape by refining with tools.
The oldest engravings on gems originated from about 5000 to 3000 B.C. The Hittites, Egytians , Assyrians, Persians and the ancient Greeks are worth mentioning for their art of carving gems. Remarkable works were accomplished by Greek artists for members of the Roman noble class during the time of early emperors. Famous examples are the Gemma Augustea ( Vienna ) and a sardonyx representing the triumph of Germanicus ( Paris ).
Seal-cylinder Gemma Augustea Engraved quartz ring with portrait of Marciana(?)
Since the time of Constantine the Great engravings on gems representing religious subjects were made in Byzantium. Our knowledge of ancient glyptograhpy is based on the collections of the important museums and on the abundance of gems in pieces of medieval jewelry. Although these gems are mostly pre-christian cameos re-used in christian objects.
Towards the middle of the 19th century a rapid decline of glytography began and the interest in carved gems was lost. Nowadays the noble art of glytography is mastered only by a small number of artists. A revival of glytography would certainly ad an element of special delicacy to the pictorial arts of today.
Resume of a text by Mister Heinz Goebbler, published in the " Zeitschrift der Deutschen Gesellschaft für Edelsteinkunde. Idar-Oberstein 1957 "
An interesting revival of this handcraft is on the way. Worldwide a growing number of very competent artists create astonishing engravings and gemstone sculptures.
Hubert Heldner   August 2001

Today, Idar-Oberstein is primarily known for the cutting of larger, more valuable gemstones, fantasy cuts (Fantasieschliffe), and the wholesale trade in polished gemstones (geschliffenen Edelsteinen). Every year around late September or early October, Idar-Oberstein is host to the Intergem trade show - short for the "International Trade Fair for Precious Stones and Jewellery."
There are several gemological research institutes [7] in Idar-Oberstein that include the 'German Foundation for Gemstone Research' (Deutsche Stiftung Edelsteinforschung - DSEF), Diamond Grading Laboratory (Diamant-PrŸflabor GmbH - DPL), German Association for Gemstone and Jewellery Evaluation (Deutsche Gesellschaft fŸr Edelsteinbewertung mbH - DEGEB), Research Institute for Gemstones and Precious Metals (Forschungsinstitut fŸr mineralische und metallische Werkstoffe, Edelsteine/Edelmetalle GmbH - FEE), and the German Gemmological Association (Deutsche Gemmologische Gesellschaft e.V. (DGemG).



15/09/2011

COSMOCHAOS Classical gem engraving studies


Cosmochaos Gem engraving team has done extended studies upon  classical engravings ,coming from ancient Greece, Roman period and Byzantine.You can see a small part of this work.















ABOUT ROCK CRYSTAL




Rock Crystal is the common name for colorless quartz. The material is abundant and has been used for centuries as a gem. Quartz crystals are among the earliest talismans. Examples of rock crystal objects date back to 75,000BC. Every culture on the planet has attributed magical power to quartz crystals. The Ancient Greeks prized rock crystal and believed it to be water frozen by the gods to a state of perpetual solidity. They carved the material into seals and intaglios. The Japanese considered it "the perfect jewel", symbolizing patience and perseverance, the infinity of space and purity. Native Americans used quartz crystals as a hunting talisman and "fed" them with deer's blood.
  Crystal balls were brought to Europe from the Near East by the Crusaders. They were credited with the ability to cure diseases. In Scotland and Ireland, farmers used crystal balls to keep livestock healthy. Today, crystal balls are still used for mystical divination, gazing and New Age healing. They vary in size ranging from small beads measuring a few millimeters in diameter to the largest known crystal ball in existence. It is displayed at the Smithsonian Institution in Washington, D.C. It is called the "Warner Crystal Ball." This specimen has a weight of 48.5 kilograms and a diameter of 32.5 centimeters.


















Species: Rock crystal
Color: Colorless
Chemical composition: SiO2, silicon dioxide
Crystal system: (Trigonal), hexagonal prisms
Hardness: 7 (Mohs scale)
Specific gravity: 2.65
Refractive index: 1.544 - 1.553
Birefringence: +0.009
Color of streak: White
Absorption spectrum: Absent
Fluorescence: None



Quartz belongs to the trigonal crystal system. The ideal crystal shape is a six-sided prism terminating with six-sided pyramids at each end. In nature quartz crystals are often twinned, distorted, or so intergrown with adjacent crystals of quartz or other minerals as to only show part of this shape, or to lack obvious crystal faces altogether and appear massive. Well-formed crystals typically form in a 'bed' that has unconstrained growth into a void, but because the crystals must be attached at the other end to a matrix, only one termination pyramid is present








Rock crystal spirituality
There is no crystal whose features can be more closely connected to the spiritual worlds than quartz. This is due to its readiness and ease of programming for energy manipulations and energy mastering, communication and protection. Quartz is an excellent energy manager, capable of giving and receiving energy in different form and on different levels. Moreover, it can accept, store and transform energy. Not only can the stored energy be preserved for latter use, but also it can be additionally transmuted into any suitable form. Quartz can remove the unwanted vibrations and center one’s own energy.

Quartz purifies the aura and symbolizes a special kind of wellbeing for the whole microcosm. It enables communication with the higher planes and dimensions of existence that are beyond the visible world. Quartz amplifies the frequencies of thoughts and feelings and can elevate the human awareness significantly. There is hardly anything you cannot do with rock crystals.

To recapitulate, quartz can amplify, focus, store, transform and energize. It is a perfect crystal for focusing affirmations and prayers. It can stimulate psychic perception. It is capable of adapting to the level and speed of each individual. Rock crystal is excellent for all chakras, for working with all symbols and all astrological signs.

Clear Quartz is known as the "master healer" and will amplify energy and thought, as well as the effect of other crystals.  It absorbs, stores, releases and regulates energy.  Clear Quartz draws off negative energy of all kinds, neutralising background radiation, including electromagnetic smog or petrochemical emanations.  It balances and revitalises the physical, mental, emotional and spiritual planes.  Cleanses and enhances the organs and subtle bodies and acts as a deep soul cleanser, connecting the physical dimension with the mind.  Clear Quartz enhances psychic abilities.  It aids concentration and unlocks memory.  Stimulates the immune system and brings the body into balance.  Clear Quartz (Crystal Quartz, Rock Crystal) harmonises all the chakras and aligns the subtle bodies