Genuine Rainbow Tourmaline AAA faceted bracelet
Genuine Rainbow Tourmaline AAA faceted bracelet
This is a Gorgeous multi color teardrop Tourmaline bracelet. Natural High Grade colorful faceted Tourmaline with hand carve delicate Clear Quartz flower make it become an unique, elegant bracelet. There is a 5 cm extension.... Show more
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Facets are flat faces on geometric shapes. The organization of naturally occurring facets was key to early developments in crystallography, since they reflect the underlying symmetry of the crystal structure. Gemstones commonly have facets cut into them in order to improve their appearance.
Of the many hundreds of facet arrangements that have been used, the most famous is probably the round brilliant cut, used for diamond and many colored gemstones. This arrangement of 57 facets was calculated by Marcel Tolkowsky in 1919. Slight improvements have been made since then, including the addition of a 58th facet (a culet) on the bottom of the stone. Since this is calculated to show maximum brilliance, round diamonds are rarely cut in any other arrangement, although recently the Princess cut is becoming popular. Other cuts, including "rose" cuts, are most typically found in antique jewelry. See diamond cuts for an in-depth discussion and diagrams of various shapes and ways of cutting faceted stones.
The art of cutting a gem with facets is a very precise activity. The aim with a faceted cut is to produce an article that sparkles with internally reflected light, and that shows off the "fire" of the stone. Accordingly, only transparent or translucent stones are usually faceted.
The angles between each facet are precisely calculated. As the aim is to maximise the effect of the internal reflections, these angles depend on the refractive index of the material. This means that although the name and general shape of a particular cut may be the same between different materials, the actual angles will be slightly different, for the maximum effect.
Thus, although cubic zirconia and rock crystal may look similar to diamond, and all can be cut in a round brilliant cut, the angles must be different to produce the same optical effects. Additionally, as diamond has a refractive index significantly higher than the other natural transparent stones, it can have a much greater sparkle than other materials.
While some facets can be cut by cleavage, specialised machines are used for cutting arbitrary facets. These consist of two main features:
a flat abrasive, usually diamond dust of precise size bonded onto a metal disk (called 'laps') or carried by an oily fluid on a smooth metal or ceramic disk, and
a system for holding a stone onto the disk at a precise angle and position.
This usually requires the stone to be attached to a holder or dop, which is then placed in an indexed vice. This allows progressively finer abrasives to be used without disrupting the orientation of the stone. The final abrasive must be smaller than the wavelength of light, so that the scratches it creates are invisible. Modern machines tend to have indexed gears for moving the stone, so that rotating the stone to cut the next facet can be more precisely controlled.
An older machine called the jamb peg faceting machine used wooden dop sticks of precise length. By placing one end into one of many precisely located holes in the jamb peg, the other end, with the stone, could be precisely placed onto the lap. These machines took considerable skill to use effectively.
Much less commonly, faceters use cylindrical machines, which leave concave facets. This technique is most noticeably used around the gem's girdle.
Phantom usually occurs in rock crystal, but is also found in smoky , , and . Rock crystal is transparent and colorless . It commonly occurs inside veins where it crystallizes in rock cavities known as vugs or pockets Phantom crystal shapes can sometimes be seen in the interior of , outlining an earlier stage of the crystal's formation.
These phantoms are usually composed of other minerals such as chlorite, goethite or hematite are composed of other varieties of such as milky , smoky or even which form on most or all of the surfaces of the crystal at a particular point in time during its growth, after which the crystal resumes its crystallization enclosing the phantom crystal outline within itself.
Phantom is recognized by its characteristic phantom crystal within itself. It can be identified as by its crystal habit, transparency, hardness, and glassy luster.
Ancient and yet always at the height of current fashion: that is for you. Its brilliant sky-blue belongs to the all-time favourite trend colours in the world of fashion and jewellery.
In many cultures of the Old and New World this gemstone has for thousands of years been appreciated as a holy stone,
a good-luck-charm or a talisman. It is a virtual "peoples gemstone". The oldest proof for this lies in Egypt, where in tombs from the period around 3000 B.C. there were found artefacts set with Turquoise. In the ancient Persian Kingdom the sky-blue gemstones were originally worn around the neck or on the hand as protection to ward off unnatural death. If the stones changed their colour, there was an imminent danger for the wearer. However, in the meantime it has been uncovered that Turquoises may in fact change their colour, but this reaction is not necessarily an indication of danger impending. The reason for the colour change is rather the influence of light, cosmetic products, dust or even the ph-value of the skin, which may all trigger off chemical responses.
Turquoise will protect and let you enjoy life
In earlier times Turquoises were sometimes thought responsible for the material wealth of their bearers. For example, Persian philosopher Al Kazwini wrote: "The hand wearing a Turquoise and using it as a sealing stone, will never be poor." Turquoises were loved as ornaments decorating turbans, often set in a border of pearls, in order to protect the wearer from the "evil eye". They were used as talismans decorating daggers, scimitars or the horses bridles. Turquoise came to Europe only during the time of the crusades. And from this period comes the name "Turquoise", meaning simply "Turkish stone".
Also in South, Middle and North America Turquoise has always been enjoying a special position among gemstones. For example, the ancient Aztecs in Northern Peru used to decorate their ceremonial masks with this stone, a "holy stone" in their belief. The North American Indians, who are still producing quite a few pieces of traditional silver jewellery set with Turquoises today, believed that the gemstone the colour of the sky would establish a direct connection between the sky and the lakes.
At all times in history Turquoise was worn as protection to ward off the influence of dark and evil powers. In former times thought to protect riders and horses from accidental falls, they are nowadays considered the ideal good-luck stones for aviators, flight staff and other professions which need special assistance to ward off accidents.
In the contemporary teachings of the Healing Power of Stones, wearing Turquoise is recommended to solve the problems caused by a depressed outlook on life. The bright and happy colour is supposed to lend self-confidence to subdued personalities, and it is also very popular as a token of friendship, since Turquoise is reputed to be responsible for faithfulness and reliable relationships.
The blue from copper, the green from iron
Turquoise is a copper aluminium phosphate achieving hardness six, thus considerably softer than . It occurs naturally in all shades ranging from sky-blue to grey-green, usually in such locations where copper is hidden in the soil in high concentrations. However, only the best quality Turquoises show the real turquoise colour, which in ordinary stones is normally rather pale, blue-green or greenish. The blue colour is caused by copper, while the green colour is caused by iron or chromium. Often the material is veined or shows spots, which depending on the respective occurrence are brown, light grey or even black. These vivid, more or less regular patterns are called the spider web. The micro-crystals are really tiny and almost not discernible with the bare eye. Usually turquoise occurs as encrustation, in veins or as nodules or nuggets. The most famous occurrences are situated in the USA, Mexico, Israel, Iran, Afghanistan and China. The most beautiful of Turquoises in wonderful light blue are found in Northern Iran.
Turquoise is only rarely facetted. Usually it is shaped as cabochons or as beads, or even given a fancy cut.
Wax will lend Turquoise resistance
Turquoises are relatively soft gemstones and thus quite sensitive. Since the colour may also fade out in the course of wearing, today even the top qualities receive a waxing and subsequent hardening treatment. This procedure will make the sensitive gemstone sturdier. Turquoises which have been sealed with artificial resin are also available in large amounts and at competitive prices.
Due to their high sensitivity, then, almost all Turquoises have been treated to preserve their beauty, however, the kind of treatment differs considerably. It makes sense, then, that naturally beautiful stones which have simple been waxed or hardened with artificial resin achieve higher prices and are more valuable than such stones, which have received colour-enhancement. Valuable Turquoise jewellery should therefore best be purchased from a jeweller you can trust.
A piece of sky in your hands
The best Turquoise quality shows a clear and light sky-blue. The colour is highly appreciated, with or without the fine regular spider web lines. The quality decreases with the increase of green in colour, and the increase of spots and irregularities in the spider web.
Turquoise should be protected from cosmetics, heat and bright daylight. The gemstone does not really appreciate sunbathing. It is recommended to clean it from time to time after wearing with a soft cloth. The colour of a Turquoise will make you feel happy and relaxed, for it combines the light blue of the sky with the invigorating green of the seas. It is so unique that the language took the stones very name to describe it: Turquoise. So if you decide on a Turquoise, you will hold a piece of the sky in your hands.