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pique Pirie Diamond Pitt Diamond PDF Print E-mail
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Sunday, 23 September 2007

pique (pee-kay"). From the French meaning pricked. A term used by some importers as an imperfection grade. The original use of the word was confined to those stones that had tiny, difficult-to-find inclusions. It has been used with increasingly poor stones until 1st, 2nd and 3rd pique grades now sometimes fit in between or replace slightly imperfect and imperfect. Some importers still use the terms 1st, 2nd and 3rd pique for grades just below flawless or per­fect, and others for categories of the imperfect grade. Sometimes ab­breviated RK. See clarity grade; rk.

Pirie diamond. A one-carat blue di­amond bought by Edwin W. Streeter in Paris in 1877. Streeter believed that it came from the recutting of the French Blue. Its present whereabouts is unknown and no other historical details are available.

pit. An indentation on the surface of a diamond. It may be caused by a blow or by a knot being pulled out from the surface during the polishing operation. A fairly large indentation is usually called a cavity; a minor one, a nick. See percussion mark.

Pitt diamond. See recent diamond.

P.K. An abbreviation often used for pique. See pique, clarity grade.

placer. Alluvial deposit of heavy minerals concentrated on the surface by moving water or air. Usually a loose mass of gravel, sand, or similar material resulting from the crumbling and erosion of solid rocks containing valuable minerals such as gold, platinum, tin, Diamonds, and other Gemstones. In most cases the gems or metals can be collected by washing or amalgamation without milling. See alluvial

planned leakage. See leakage.

Platberg diamond. Although dia­monds have been reportedly found in Africa prior to 1860, one of the first documented stones is the Plat­berg diamond. Its occurrence is re­corded in the daily diary of the Pniel Station of the Berlin Mission Society. This 5-carat stone was found by a na­tive in 1859 on the riverbank of the Vaal River near Platberg, Republic of South Africa. It was later purchased by a Mission priest for £5. Its present whereabouts is unknown.

Pliny the Elder. A Roman naturalist and one of the earliest authors to de­scribe the diamond (77 A.D.): "a

 
pink diamond Pionersky Diamond pinpoint PDF Print E-mail
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Sunday, 23 September 2007

pink diamond. A fancy diamond. A lerm often used loosely in the trade lo describe any light red, light purple or light purplish-red diamond. Those olher than light red are sometimes described by such terms as rose pink, iose colored, peach blossom and heliotrope. See le grand conde' dia­mond, PEACH-BLOSSOM diamond, WILLIAMSON diamond, NUR-UL-AIN diamond, DARYA-I-NUR HIAMOND, PRINCIE diamond, WINSTON PINK NIAMOND.

pinpoint. (1) Any small rounded in­clusion seen at 10x but not large


enough to be discernible as an in­cluded crystal. (2) Essentially, the same as "carbon spots" which are somewhat more likely to be opaque.

Pionersky diamond. One of many large (weight unreported) named rough diamond crystals in the Rus­sian diamond Fund at the Kremlin.

pipe. The common name for a verti­cal, cylindrical or columnlike mass of rock that cooled and solidified in the neck of a volcano. When these rock masses are composed of kimberlite, they sometimes contain dia­monds. Although the kimberlite in the various pipes is similar, the pipes Ihemselves differ in size and shape and in the kind of Diamonds they produce. Kimberlite pipes occur in Arkansas, India, the Republic of South Africa, the Republic of Zaire, Russia and elsewhere. See kimberlite.

 
Pigott Diamond pile pile-treated dimond Pindar Diamond PDF Print E-mail
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Sunday, 23 September 2007

Pigott diamond. It was in the year 1818 when Ali Pasha of Janina, ruler of Albania and an enthusiastic gem collector, decided to purchase a large diamond from the London jewelry firm of Rundel & Bridge for $150,-000. Apparently, he was jealous of his newly acquired bauble and kept it in a little green leather bag inside his sash, seldom showing it to others. In 1822, the Sultan of Turkey, over­lord of Albania, became resentful of Ali Pasha's mounting power and in­dependence and sent an emissary to demand his surrender. The 80-year-old Pasha was mortally wounded in the palace scuffle that ensued. As he lay dying in his own throne room, he summoned a faithful soldier of fortune, a Captain d'Anglas, and or­dered him to destroy his two most precious possessions: the diamond and his wife, Vasilikee. Although the stone was reported shattered before his eyes, he failed to live long enough to insist on his wife's death and she escaped. This ill-omened stone, called the Pigott, was a fine-quality, oval-shaped Indian diamond, variously said to have weighed from47 to 85.80 carats. Most authorities agree to 49 carats. It was named for Baron George Pigot (the correct spell-int of the name), twice Governor of Madras, who was thought to have acquired it as a gift from an Indian prince in 1763 and willed it to a sis­ter and two brothers in 1777. Sub­sequently, it changed hands several times (once by lottery in 1801) and was said to have been owned at one time by Madame Bonaparte, mother of Napoleon. Since the death of Ali Pasha, there has been no trace of the Pigott; likewise, there is no actual evidence of its destruction. Only the model, which had been made previ­ously in England, remains. A less fre­quently used name is the Lottery Di­amond; an alternate spelling is Pigot.

See QUEEN OF ALBANIA diamond.

pile. A term used for the first nuclear reactor made by piling up graphite blocks and pieces of uranium and uranium oxide. See pile-treated dia­mond.

pile-treated diamond. A diamond whose color has been changed to green or yellowish green (or, if treated too long, to black) by bom­bardment with neutrons in a radioac­tive pile. Subsequent heat treatment may result in still further color change. See pile, nuclear reactor, cy­clotron TREATED.

Pindar diamond. Sir Paul Pindar brought this stone to England from Constantinople and sold it to Charles I. Valued at $150,000. Thought to have been among the royal jewels on which Henrietta Maria, his wife, raised $10,000 in one year. Sub­sequent history lost.

 
Piaui picotite piedra del cabo Piermatic Automatic Diamond Polishing Machine PDF Print E-mail
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Sunday, 23 September 2007

Piaui. A state in Brazil and a minor producer of Diamonds. See brazil. picking table. A flat or slightly in­clined platform on which diamond-bearing ore is distributed to remove unwanted materials. It was used in the South African diamond mines until the effectiveness of grease sep­aration was discovered accidentally. It is still used in some small opera­tions.

picotite. A dark-brown, translucent to almost opaque variety of spinel; a primary mineral in the kimberlite oc­currences of South Africa. At one time it was suggested as constituting many of the dark-appearing inclu­sions in diamond, but this was not confirmed by later research.

piedra del cabo. The Spanish term for South African diamond.

Piermatic Automatic diamond Polishing Machine. The Piermatic unit was invented by Mr. M.Liebowitz, a South African civil en­gineer, and developed by the Dia­mond Trading Company in the mid-1960's and early-1970's. It is limited to the cutting of round brilliant dia­monds. Reportedly, it is best suited for processing sawn crystals (four-point Diamonds) between 0.20 carats through 0.60 carats. The unit com­pletely polishes the pavilion facets, lower and upper girdle facets, and bezel facets. The star facets, table facet and culet (if any) must be polished by the traditional (non-automated) method. The newer Piermatic II is an improved Piermatic Machine.

pierres de fantasie. A French term meaning fancy-colored Diamonds.

piggy-back diamond. An "assembled stone" composed of a flat diamond with a large culet set above, but not touching, a smaller diamond result­ing in the appearance of a much larger stone when viewed from above.

 
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.

 
Oval Elegance Ovalumpally Mine o overspread stonevergrowth oxidized crystal PDF Print E-mail
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Sunday, 23 September 2007

Oval Elegance (trademark). A 58-

facet oval cut marketed by the diamond-cutting firm of Lazare Kap­lan & Sons, Inc. It is claimed by the producer to enlarge the apparent size of a diamond and to produce more brilliance than other fancy cuts. See

OVAL CUT

oval marquise. A marquise cut in which the typical boat-shaped out-


line has blunted rather than pointed ends. See marquise.

Ovalumpally Mine. The name of an old diamond mine in the Madras dis­trict of India. Same as woblapally mine,

overblue. A term applied to a dia­mond that has a bluish cast in day­light; usually a fluorescent stone. See

FLUORESCENCE.

overgrowth. A thin coating of cal­cium carbonate found on some dia­monds that prevents them from adhering to the grease table. overspread stone. See swindled stone.

oxidized crystal. A diamond crystal that contains iron oxide. In some Diamonds, surface oxidization has probably taken place due to contact with the atmosphere during forma­tion of an alluvial deposit. The ox­idized substance is usually yellow, orange or red, and its presence often imparts a false color to the crystal. In some other Diamonds the oxidation is nearly always inside the crystal; it is very seldom a coating. See star of

SIERRA LEONE diamond.

oyster line. See namaqualand.

Ozark diamond Company. One of

the companies that was organized to mine the Arkansas diamond deposits.

See ARKANSAS.

 
Orpin-Palmer Diamond out-of-round diamond oval cut PDF Print E-mail
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Sunday, 23 September 2007

Orpin-Palmer diamond. The first of several large South African alluvial Diamonds found (1902) on the Vaal River Estate, Cape Province. Valued at £ 100, it was said to have been a 117.5-carat dull-white diamond. Its present location is unknown.

Ortlepp diamond. An uncut tri­angular-shaped stone (made) re­ported to be smaller than a shirt but­ton, and believed by some to be the first diamond discovered in the Kim-berley diggings. It was found in July, 1869 by Mrs. Sarah Ortlepp while resti ng u nder a shade tree. The Ortlepp stayed with the family for six genera­tions and is now on permanent loan to the Africana Museum in Johan­nesburg.

Otto Borgstrom diamond. A

121.50-carat, well-formed, yellowish octahedron that was found in the Gong Gong diggings on the Vaal River, Cape Province, Republic of South Africa, in 1907. The present whereabouts of this stone is not known.

Otto's Kopje (kop"-e). A small dia­mond pipe mine in the Kimberley area, Cape Province, Republic of

South Africa. Unlike the roughly cir­cular shape of most volcanic pipes, it is a wide and irregular volcanic fis­sure.

Oubangui-Chari. Formerly a territory within French Equatorial Africa, now the Central African Republic. Sig­nificant diamond production comes from both East and West Oubangui.

See EAST OUBANGUI, WEST OUBANGUI.

out-of-round diamond. A term used to describe any brilliant or other style of round-cut diamond that does not have a truly circular girdle outline to

the eye; a stone with a girdle circum­ference that is appreciably oval or squared but not constituting a fancy shape. See symmetry

outside goods. diamond rough sold by the diamond Trading Co., Ltd., which has been purchased either from the diamond Producers' Association, Ltd., or from such other sources as Angola, Ghana or Sierra Leone. That purchased from other than a mem­ber of the Producers' Association is


lermed outside goods. Outside goods also refer to those sold "outside" of the diamond Trading Co., Ltd.

oval brilliant cut. See oval cut

oval cut. (1) A brilliant style of cut-ling in which the girdle outline is el­liptical; i.e., a rounded oblong. Also called the oval brilliant cut. (2) An obsolete barrel-shaped style of cut­ting with a circular cross section and covered with triangular facets.

 
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