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Phoenix Mine phosphorescence photoluminescence Photostand PDF Print E-mail
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Sunday, 23 September 2007

Phoenix Mine. A small diamond pipe mine in the Winburg area, Orange Free State, Republic of South Africa.

phosphorescence (foss"-fo-ress'-cence). A variety of luminescence. The property possessed by some di­amonds and other Gemstones of con­tinuing to emit visible light in dark­ness after exposure to X-rays, cathode rays, ultraviolet rays or visi­ble light. It differs from fluorescence, which is an emission of visible light during exposure. Phosphorescence is a continuance of luminescence after the removal of the exciting rays, and a phosphorescent stone or other ob­ject is said to phosphoresce, or glow. Phosphorescent Diamonds are un­usual. See FLUORESCENCE, FLUOROCHROMA-TIC, LUMINESCENCE, PHOTOLUMINESCENCE, PRE­MIER diamond, ULTRAVIOLET, ULTRAVIOLET LAMP. CHAMELEON diamond.

photoluminescence (fo'-toe-loo'-ma-ness"-cence). The property of some Diamonds and other Gemstones to become luminescent when ex­posed to the action of visible or ul­traviolet light rays only. They are said to be fluorescent if luminescent dur­ing exposure, and phosphorescent if luminescent after exposure. See emis­sion SPECTRUM, FLUORESCENCE, LUMINESCENCE, PHOSPHORESCENCE, PREMIER diamond, UL­TRAVIOLET

Photostand. The GEM Photostand is an especially designed system for photographing jewelry. The unit con­sists of a Polaroid Automatic Land Camera with cable release, auxiliary Vi size, actual size, and \Vi size color-coded lenses and electric eye adaptor. The stand has a scientifically balanced color-corrected lighting system, with focusing and centeringndicators. It uses black and white or color film.

 
Peruzzi cut phenomenal diamond Pesas diamond Philip II Diamond PDF Print E-mail
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Sunday, 23 September 2007

Peruzzi cut. See peruzzi, vincenzio. Peruzzi, Vincenzio. A 17th century Venetian lapidary who is credited with first revealing the true beauty of the diamond by employing the bril­liant form of cutting; i.e., with 56 facets, a table and a culet. Some­times referred to as the Peruzzi cut, it was an improvement over the earlier Mazarin cut.

Pesas diamond. A misnomer for rock crystal.

phenomenal diamond. A general term for any diamond that displays an unusual optical effect. See

FLUORESCENCE, PHOSPHORESCENCE, FLUORO-CHROMATIC, TRANSICHROMATIC, PREMIER DIA­MOND.

Phianite. Trade name for man-made cubic zirconia.

Philip II diamond. A 47.50-carat diamond, supposedly purchased by Philip II, of Spain, in 1559. Further details lacking.

philosopher's stone. An imaginary stone, the use of which medieval al­chemists believed would transform flint into gold or into diamond and other precious stones.

 
pear-shaped rose cut pectolite penetration twin PDF Print E-mail
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Sunday, 23 September 2007

pear-shaped rose cut. A rarely used rose style of cutting that has a pear-shaped girdle outline, a flat, unfa-ceted base and a pointed, dome-shaped crown bearing 24 triangular facets; the number of facets, how­ever, may vary. Pecos diamond. A misnomer for rock


crystal from the Pecos River, Texas, or New Mexico.

pectolite. A subtranslucent, whitish or grayish secondary mineral found in the Kimberley diamond pipes; sometimes deposited in fissures of deep fractures in the surface of dia­mond crystals.

Pelikanstraat. The famous street in Antwerp, Belgium, about which the diamond-cutting industry centers. pendant-cut brilliant. The anglicized name for a pendeloque. pendeloque (pahn"-dah-loke). A modification of the pear-shaped bril­liant cut. It has an outline similar to the pear shape, but with the nar­rower end longer and more pointed.

penetration twin. A twin crystal in which the two or more parts appear to interpenetrate one another. The parts have some definite angular re­lationship to one another with respect to the axis of twinning. Pene­tration twins of cubes, tetrahedra and other forms are sometimes encoun-lered in diamond.
 
Paphos diamond Parisian diamond SYNTHETIC DIAMOND Parteal Mines PDF Print E-mail
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Sunday, 23 September 2007

Paphos diamond. A misnomer for rock crystal.

Para. A minor diamond-producing state in Brazil. See brazil.

Paphos diamond. (1) A term that seems to have been used first in the 16th cen­tury for Diamonds weighing mine than 12 carats. (2) A term once used by jewelers to mean "Diamonds free from specks or foulness." (3) A per feet diamond weighing 100 carats or more.

Paphos diamond. A collection made up ol clearly defined groups of Diamonds, which, after evaluation, is ready for sale. See lot and sights.

Parisian diamond. An old misnomer for a diamond imitation. Parsons, Hon. Sir Charles Algernon (1854-1931). An English engineer m\<\ inventor who, in 1918, attempted lo produce synthetic Diamonds by re peating the experiments of Moissan and Crookes with variations, and was convinced that these methods could not be successful. In one novel experiment he fired a blank shotgun shell against the piston of a compres sion chamber that was filled wilh carbon. When this was unsuccessful he sought still higher pressures by discharging bullets into a tapered carbon-filled hole in a steel block. Pressures of 5000 tons per square inch were supposedly obtained in this manner. There is no proof that his experiments were successful, See

SYNTHETIC diamond; MOISSAN, FERDINAND FREDERIC HENRI; CROOKES, SIR WILLIAM,

Parteal (or Partial) Mines. A group ol old diamond mines near Golconda, India, some of which were worked as late as 1850. Located on the north bank of the Kistna River, east ol the Kollur Mines, and at the junction ol the Kistna and Munyero Rivers. Said to have had large production from an alluvium of a decomposed cli.nnan tiferous stratum. See col< onda, itvii >i-v

 
painted diamond Pam Diamondpampille cut pan Panna District PDF Print E-mail
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Sunday, 23 September 2007

painted diamond. See coated diamond. Pam Brilliant diamond. See pam dia­mond.

Pam diamond (or Pam Brilliant). diamond that weighed between 112 and 115 carats (authorities differ) when found, supposedly sometime before 1891, in the Jagersfontein Mine, Republic of South Africa. After the gem was cut into a 56.6-carat brilliant, it is said to have attracted the attention of Queen Victoria. She asked to have it shown to her at Os­borne House. At that time, the Duke of Clarence, her grandson and heir to the throne, was engaged to marry Princess May of Teck (later Queen Mary). The untimely death of the young Duke in 1892 put an abrupt end to the negotiations. The present location of this stone is not known. An alternate name for it is the jagersfontein Brilliant diamond.
(pam-peel"). A dropshape that is related closely to the briolette; it has the circular cross sec­tion of the briolette but is usually more elongated. It is covered with rows of facets of different sizes and shapes that become smaller as they approach the lower point of the stone. This form of cutting is rarely encountered. (See diagram.)

pan. A South African name for a natural land basin. In several areas of the South African plateau, the sur­face rock is more resistant to erosion than diamond-bearing kimberlite, so the point at which a pipe reaches the surface in such an area is a depres­sion, or pan.

Pan, The. A name once used by the South African diamond diggers for the Dutoitspan Mine. pane facets. A little-used name for star facets.

Panfontein Mine (Pan'-fonn-tane").A small diamond pipe mine in the Koffiefontein area, Orange Free State, Republic of South Africa.

Panna diamond-Mining Syndicate.A diamond-mining company in the Panna district, Madhya Pradesh, In­dia. See india.

Panna District. The area in India in which the principal diamond mines are located. See india.

panning. The act of separating dia­monds from other materials by mix­ing the gravel with water in a pan


and shaking the pan with a rotary motion, thus decanting the lighter materials off the top.

Paolo de Frontin diamond. Reported to be a slightly greenish-yellow 49.50-carat rough Brazilian dia­mond. It was sold in London in 1936. No other information is available.

paper marks. The fine scratches or abraded facet edges on paperworn Diamonds.

paperworn diamond. A diamond with one or more abraded facet edges or scratches on either pavilion and/or crown facets, resulting from being carried loose in a diamond paper with other Diamonds.

 
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