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pure purest water Putfontein Pypklip PDF Print E-mail
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Sunday, 23 September 2007

pure. A rarely used term that refers to comparative perfection; more or less synonymous with clean

. purest water. A little-used quality des­ignation for highly transparent dia­monds of fine color. See water.

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

Puruni River. A source of Diamonds in Guyana, formerly British Guiana.

See GUYANA.

Putfontein. A minor alluvial dia­mond deposit in the Lichtenburg area, Transvaal Province, Republic of South Africa.

Pypklip. One of the more important alluvial diamond deposits in the Lichtenburg area, Transvaal Province, Republic of South Africa. Production figures from this area for one recent year credited Pypklip with approxi­mately 2050 carats.

pyrope. This species of the garnet group is used as an indicator of the presence of Diamonds. It is resistant to wear and can survive being trans­ported many miles from its source
 
Progress Diamond proportion of diamonds to blue ground proportions ProportionScope Punch Jones Diam PDF Print E-mail
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Sunday, 23 September 2007

Progress diamond. An 80.66-carat rough diamond found in the Mir pipe. Now in the U.S.S.R. diamond Fund in Moscow.

proper proportions (of a diamond).

See AMERICAN CUT; TOLKOWSKY, MARCEL; PRO­PORTIONS; PROPORTIONS, GOOD.

proportion of Diamonds to blue ground. See richness of maior diamond

DEPOSITS, RELATIVE.

proportions. A term that meant orig­inally the distribution of the mass of a fashioned diamond above and below the girdle. Use by diamond men has broadened its meaning to include the major factors that deter­mine cutting quality; i.e., total depth as a percentage of the girdle diame­ter, table diameter, girdle thickness, facet angles, symmetry, and even de­tails of finish. See proportions, good;

CUTTING; AMERICAN CUT; TOLKOWSKY, MARCEL; FINISH; SYMMETRY.

ProportionScope. A diamond-grading instrument designed and first manufactured by the Gemological Institute of America in 1967. It is an optical comparator for the checking of the proportions of a brilliant. It combines lenses and movable mir­rors to project the silhouette of a dia­mond on a screen. Line diagrams of Tolkowsky proportions on the screen, as well as a "zoom" range, enable

proportions, good. The proportions derived mathematically for the op­timum treatment of light are seldom cut today. Present tastes among jewelers apparently have been con­ditioned somewhat by the weight saving and cost reduction made pos­sible through "spreading," for slightly larger tables and thinner crowns. However, there is general agreement that the angles of the Tolkowsky Theoretical Brilliant Cut are op­timum, so any stone of good propor­tions should have a 403/4° pavilion angle, 34 Vi" crown (bezel), (and a girdle of medium thickness). See

AMERICAN CUT, SPREAD STONE, SWINDLED STONE, PROPORTIONS.

Province of the Cape of Good Hope (also called Cape Province or the Cape). A province in the Republic of South Africa, the north-east and east-central portions of which have been, and are, important diamond-producing areas. The famous mining town of Kimberley is in Cape Prov­ince near the boundary of the Or­ange Free State.

puinwassers. A term used to describe washers of old tailing (waste washers) in the South African dia­mond fields. pulsator jig. See jig.

Punch Jones diamond. One of the largest United States Diamonds, this 34.46-carat greenish-gray crystal was found in 1928 on Rich Creek near Peterstown, West Virginia. It was dis­covered by Grover C. Jones and his son, William R "Punch" Jones, while playing horseshoes but was not posi­tively identified as a diamond until 1943, when it was examined and tested by Professor Roy J. Holden of Virginia Polytechnic Institute. It is now on permanent display in the Smithsonian Institution, Washington, D.C.

 
Princess Mathilde Diamond Princie Diamond Prinz cut profile cut PDF Print E-mail
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Sunday, 23 September 2007

Princess Mathilde diamond. Mathilde was the cousin of Louis Napoleon (later Napoleon III of France) and hostess for him until his marriage to Eugenie de Montijo; this diamond is thought to have been named for her. Mathilde, who was married to Prince Anatole Demidoff of Russia, had magnificent jewels. Later, the diamond was also said to have belonged to the great collector, Abdul Hamid II, Sultan of Turkey. Still later, in 1933, it was sold to an undisclosed buyer in Paris by the Monte de Piete (National Pawnshop), which described it as "a brilliant of 16.25 carats and of a special shape that closely resembles the hexag­onal."

Princie diamond. The Princie Dia­mond, which apparently has no pre­viously recorded history, is thought to have belonged to the Nizam of Hyderabad at one time. It is a pink, cushion-cut stone of 34.64 carats. In 1960, it was sold at auction by Sotheby's to the London branch of Van Cleef & Arpels for $128,000 and sent to their Paris store. In the same year, it was christened the Princie at a party in its honor in Paris. Among the guests were the Maharanee of Baroda and her fourteen-year-old son, the prince heir, whose pet fam­ily name is "Princie." Van Cleef's be­lieve it to be one of the largest and finest pink Diamonds in the world; it is mounted as a pendant and sur­rounded by large white brilliants on a slender necklace of baguettes.

Prinz cut. A small, simple polished 5 faceted octahedron.

proclaimed area. A term used in the Republic of South Africa for diamond-bearing claims or land that have been proclaimed by the government-owner for the issuance of digger's licenses. See deproclaimed

AREA, RESTRICTED ALLUVIAL DIGGING.

profile cut. A diamond cut invented in 1961 by Mr. Arpad Nagy, founder of the diamond Polishing Works in London. The cut makes economical use of flat crystals in order to provide a large surface area of diamond at a low cost. It was initially called the

Princess cut. Flat crystals are gang-sawed into parallel plates about 1.5 mm. thick. The plates are then cut into a variety of desired shapes and the top surface polished. A series of narrow parallel grooves are cut on the bottom of each plate which gives the required total internal reflection to make it lively, but it lacks fire. See

Princess CUT.

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premium prices Presidente Dutra Diamond Getulio Vargas Prince Edward of York Diamond PDF Print E-mail
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Sunday, 23 September 2007

premium prices. (1) Prices above the normal trade prices that are asked for certificated stones. These prices,however, do not apply to all dia­monds with certificates. Premiums are only paid for Diamonds of certain grades and sizes. (2) Premium prices also refer to percentages over theDiamond Trading Company's list price on "original" series from DTC.Thus, a premium of 5% means theprice is 5% over the DTC selling
price.

Presidente Dutra diamond. A 409c arat diamond that was found in 1949 by a prospector in the ouradinho River, Coromandel district, Minas Gerais, Brazil. From it were cut 36 stones totaling 136 car ats, the largest of which weighed 9.60 carats and the smallest, .55 car ats. Also called the Dutra diamond.

the San Antonio River, municipality of Coromandel, Minas Gerais, Brazil, by a native prospector and his part­ner, a farmer. It was named in honor of the then president of that country,


Getulio Vargas. The partners sold the stone to a broker for about $56,000 and it changed hands several times, eventually reaching a reported value of $235,000. Harry Winston, New York City gem merchant, bought the stone in 1939 for approximately $600,000. In 1941, Winston had it cut into 29 stones, the important ones of which were all emerald cuts. The largest of these, which weighed 48.26 carats, is known as the Vargas or Presidente Vargas diamond. It was owned for a number of years by Mrs. Robert W. Windfohr of Ft. Worth, Texas, but later came back into the possession of Harry Winston. Own­ership of the other stones is not known Presidente Vargas diamond. With a weight of 726.60 carats, the Pres­idente Vargas diamond qualifies as one of the largest Diamonds ever found. It was discovered in 1938 in

Prince Edward of York diamond. A

60.25-carat, fine-quality, pear-shaped African stone that was imported to the United States in 1901 by Alfred H. Smith & Co. and sold to a New York banker. Ultimate disposition unknown.

Princess cut. An earlier name for the profile cut invented by Arpad Nagy in 1961. Also applied, for a time at least, to the 144-facet round brilliant. See profile cut.

 
Premier Mine premium PDF Print E-mail
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Sunday, 23 September 2007

Premier Mine. (1) The name that was given originally to the Wesselton Mine; references prior to 1903 are to that mine. (2) After 1903, the name referred to the mine located 25 miles east of Pretoria, South Africa, owned by the Premier (Transvaal) diamond Mining Co., of which Thomas Culli-nan, the discoverer of the mine, was chairman of the board. The mine was discovered in 1902 and was bought for £ 52,000. In 1905, its production reached 24,000 loads a day, which, for that time (and even for today), is a tremendous produc­tion for a diamond mine or for any


kind of mine. It was closed in 1932 and operations resumed in 1947, when it was operated as a shaft mine, rather than as an open-pit mine. It is the source of the largest gem diamond ever found: The 3106-carat Cullman diamond. In­dustrial Diamonds represent approx­imately four-fifths of the total produc­tion. The remainder are Gemstones, some of which, particularly those of a blue color, are of very fine quality. The total annual output in 1975 was 2,036,000 carats of which 605,000 carats was gem quality. From 1903 to 1960, approximately 148,841,000 tons of blue ground were mined to recover 42,842,172 carats of dia­monds; i.e., about 18,856 pounds. Premier (Transvaal) diamond Min­ing Co., Ltd. See premier mine.

premium. The difference between premium price and uncertificated price. Premiums, usually expressed as a percentage, are not necessarily fixed, but may fluctuate with supply and demand, the economy, and the prevailing diamond market at the time.


 
Portuguese West Africa Potaro Riv er potentially flawless Premier Diamond Precious Stones PDF Print E-mail
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Sunday, 23 September 2007

Portuguese West Africa. A name formerly used for Angola, a major diamond-producing country. See an

COLA.

Potaro River. A source of Diamonds in Guyana, formerly British Guiana.

See GUYANA.

Potchefstroom. A town in Transvaal Province, Republic of South Africa, and the location of minor alluvial diamond deposits.

Potemkin diamond. See empress euce'nie diamond.

potentially flawless. A term used in the preliminary description of a dia­mond which could possibly be re-polished or recut so as to rate an in­ternally flawless or a flawless grade. Although the weight loss involved is usually small, the demand and price for flawless grades are such that some­times considerable weight is sac­rificed to achieve them. See flawless.

pothole. A circular hole worn into solid rock by the churning action of water on loose stones and sand that abrade the rock. Usually greater in depth than in width. Heavy minerals (diamond, for example) tend to re­main as concentrates, so the potholes, if in an area of diamond-bearing gravels, may contain excep­tionally valuable deposits. See allu­vial DEPOSITS, ABRASION, ALLUVIAL SORTING, GEM GRAVEL, WET DIGGINGS, RIVER DIGGINGS.

Practical Fine Cut Brilliant. This cut originated from practice and serves as the standard cut for judging pro­portions in Germany. With respect to the girdle diameter, a 1939 study showed a crown height of 14.4%, a pavilion depth of 43.2%, a table diameter of 56.0%, and a crown height to pavilion depth ratio of 1: 3.00. The crown angle is 33.2° and the pavilion angle is 40.8°.

Prairie Bird. A minor alluvial dia­mond deposit in the Bloemhof area, Transvaal Province, Republic of South Africa. This digging contrib­utes very little to total South African alluvial production.

Precious Stones Act of 1927. A law that gives the Government of the Re­public of South Africa complete con­trol of all alluvial diamond deposits; i.e., granting of claims and licenses, controlling production, etc.

Premier diamond. This 86.40-carat emerald-cut diamond was purchased by Harry Winston, New York City gem merchant, in 1957. It was set in a pendant-clip combination, with 157 brilliants, and sold through the Geneva office of Harry Winston, Inc., in 1958.

premier diamond. A diamond that appears bluish in daylight and yel­lowish in artificial (incandescent) light; a yellow stone that fluoresces strongly in a blue color. The term is usually applied to fluorescent stones that seem cloudy or "oily" in day­light. See FLUORESCENCE, FLUOROCIIROMA-TIC.

Last Updated ( Sunday, 23 September 2007 )
 
Porter-Rhodes Diamond portrait stone Portuguese cut Portuguese Diamond City diamond merchant PDF Print E-mail
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Sunday, 23 September 2007

Porter-Rhodes diamond. Considered to be the finest African diamond found up to that time (1880), this 153.50-carat stone came from the claim of Mr. Porter-Rhodes in the Kimberley Mine. It was valued at $200,000. In 1881, Mr. Porter-Rhodes visited Osborne House in London and showed it to Queen Victoria, who exclaimed over its great purity and beauty. Empress Eugenie, who also saw the great diamond at the same time, remarked that it was "simply perfection," not knowing what to compare it with. At that time, it was the general belief that South African Diamonds were in­ferior. Victoria asked, "Is it really from the Cape?" Eugenie remarked, "Are you sure the diamond is from South Africa, and have you not had it polished a little? I have always been under the impression that Diamonds from the Cape were very yellow and worth but little." In 1926, the gem was said to have been given as a wedding gift by the Duke of Westminster to his third wife, Loelia Ponsonby; at that time, it was an old-mine-cut diamond of 73 carats. In 1928, it came into the possession of the London jewelry firm of Jer-wood & Ward, who had it recut in Amsterdam to a 56.60-carat emerald cut. In 1937, it was reported to have been sold to an East Indian. The Porter-Rhodes diamond was pur­chased in 1946 by Harry Winston from His Highness, the Maharajah of Indore. It was subsequently sold to a client in the United States.

portrait stone. A flat style of cutting that permits one to see through to any object over which it is placed.

See bevel cux lasque.

Portuguese cut. A rarely used mod­ification of the brilliant cut, having two rows of rhomboidal facets and three rows of triangular facets on both crown and pavilion. This style of cutting is used only on large stones.

Portuguese diamond. Formerly a cushion cut of 150 carats, the Por­tuguese diamond is today a 127-carat emerald cut and is on perma­nent display at the Smithsonian In­stitution, Washington, D.C. It was presented to the Museum in the early 1960's by Harry Winston, New York


City diamond merchant. The gem is fluorescent and flawless. The name is taken from the Portuguese Royal House, with which it is said to have had an earlier connection.

 
Pomona Pontianak poorly made Porges Diamond porknocker PDF Print E-mail
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Sunday, 23 September 2007

Pomona. An area of alluvial dia­mond deposits in South-West Africa, parts of which are now virtually exhausted. Pontesinha diamond. See carbonado

PONTESINHA diamond.

Pontianak. A city on the west coast of Borneo in the vicinity of which the first diamond deposits were found.

See KALIMANTAN.

pool. Rough Diamonds formerly were sorted by the diamond Trading Co. into a number of broad classifica­tions, called pools; e.g., shapely crystals were put into one pool, and various types of distorted or twinned crystals, fragments and limited color categories into others. Some pools were available only to certain groups of cutters.

poorly made. A stone with deficien­cies in proportions or finish or both.

See FINISH; MAKE; PROPORTIONS, GOOD.

Pope Paul III diamond. Holy Roman Emperor Charles V presented this stone to Pope Paul III when he en­tered Rome in April, 1536. Ben-venuto Cellini, in his Autobiography, tells of setting the diamond in a ring for the Pope, for which he says the Emperor paid him 12,000 crowns.

Porges diamond. A 78.53-carat champagne emerald-cut diamond purchased by Harry Winston, New York City gem merchant, in 1962. The setting of this diamond consists of a very elaborate clip-pendant combination in yellow gold sur­rounded by 8 cabochon emeralds, 8 cabochon rubies and 32 old mine


Diamonds. It was sold in the United States in 1968.

porknocker. The local slang term for a native gold miner or diamond miner in Guyana (formerly British Guiana) who, although holding a mining license, is only allowed to work on another person's claim.

 
polished goods polished rough polisher polishing mark PDF Print E-mail
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Sunday, 23 September 2007

polished goods. Diamonds that have been cut and polished, as opposed to rough. See goods.

polished rough. A fashioned dia­mond whose shape and facets are to­tally unsymmetrical. See cap cut

polisher. A term used to describe any workman who places and polishes any of the facets on a diamond.

polishing. The reduction of a rough or irregular surface to a smooth flat­ness or curvature. In diamond fash­ioning, it is used to include both lap­ping, or blocking, and brillianteering, as well as the production of any facet; the final operation in fashion­ing a diamond, usually done with dia­mond powder on a horizontal disc, or lap, against which the diamond is held in a dop. See blocker, lapper, bril­lianteering, LAP DOR

polishing directions. The directions in which diamond polishes most eas­ily. In practice, this direction is usu­ally found by trial and error, although it is always away from an octahedron face and toward a possible rhombic-dodecahedron face. Facets parallel to the surface of a dodeca­hedron are the easiest to polish; those parallel to a face of an oc­tahedron are the most difficult. The ease and rapidity of polishing also varies in different directions; i.e.,


from right to left the rate may be more rapid than from left to right. See directional hardness.

polishing mark. A groove or scratch left by the polishing wheel on a facet of a diamond. Polishing marks do not run across facet junctions. Paral­lel grooves left during the initial plac­ing of facets should be removed dur­ing the final polishing to the point that they are not visible under 10x. Polishing marks are considered to be defects in finish.

polycrystalline diamond. Explosion synthesized Diamonds are hexagonal in structure and polycrystalline, i.e., they are composed of many crystals and are very hard, like carbonado. polysynthetic twinning. A form of repeated twinning, in which the twinning planes of adjacent indi­viduals are parallel. The result is a system of thin laminae, with each individual reversed with respect to the next. Polysynthetic twinning is thought by some to be the cause of the laminated effect that is seen in


some Diamonds under magnification. See twinning lines, knot lines, repeated twinning.

 
point naif Polar Star Diamond PDF Print E-mail
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Sunday, 23 September 2007

point naif (pronounced "knife"). A

term used by Tavernier in the 17th century to indicate a diamond oc­tahedron or other crystal shape hav­ing easily distinguishable natural faces. However, the term natural


point is now used in the industrial-diamond industry to mean an elon­gated diamond crystal, particularly one with sharp points. See naif. polariscope. An optical instrument that consists basically of two polariz­ing filters. The filter through which light enters is called the polarizer; that through which observations are made is called the analyzer. The in­strument is used to ascertain whether a gemstone possesses single or dou­ble refraction. It is also used to detect anomalous double refraction, which, when found in a singly refractive stone such as diamond, often indi­cates internal strain. See isotropic,

ANISOTROPIC, ANOMALOUS DOUBLE REFRAC­TION, REFRACTION, INTERNAL STRAIN.

Polar Star diamond. In layman's language, the 41.36-carat Polar Star has been described as the "brightest" diamond ever seen — a stone of in­comparable beauty and luster. Very little is known of its background, al­though it is thought to be of Indian origin. It is said to have belonged to Joseph Bonaparte, eldest brother of Napoleon I, who reputedly paid $10,000 for it. Joseph was King of Naples from 1806 to 1808, King of Spain from 1808 to 1813, and lived in the United States from 1815 to 1841. In the 1820's, the Polar Star was sold into Russia. Prince Yous-soupoff, who was living in France in 1949, stated at that time that the gem had been owned by his family for more than 100 years but was later sold to Carrier of Paris. It is now the property of Lady Lydia Deterding, Russian-born former wife of the late oil magnate, Sir Henry Deterding. The Polar Star is presently set in a ring, but detaches to form a pendant. Alternate name: Youssoupoff Dia­mond.

Pole Mine. An early diamond pipe mine in the Kimberley, Republic of South Africa area, located north of the city of that name.

polish. The relative smoothness of a surface, or the degree to which the finish of the surface approaches opti­cal perfection. A well-polished dia­mond shows no wheel marks or other surface blemishes under 10x.

 
Plymouth Diamond Pniel Pniel Estate Pohl Diamond Pointe de Bretagne Diamond PDF Print E-mail
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Sunday, 23 September 2007

Plymouth diamond. This 2.65-carat rough white diamond was discov­ered in 1934 at Amador County, California. Additional details are lacking.

Pniel. South African alluvial dia­mond diggings on the Vaal River, northwest of Kimberley, originally granted by a Koranna tribal chief to the Berlin Missionary Society. Begin­ning in 1870, the Society paid monthly lease fees of 10 shillings a claim. The finds were phenomenal. Consecutive prospecting began in June, 1870. Many claims yielded down to bedrock, 25 feet below the surface. Now called Pniel Estate, it is a minor producer.

Pniel Estate. See pniel pocaol. A Brazilian term for pits in river beds in which diamond-bearing gravel is found. See pothole.

"pocket peddler." A trade term that refers to sellers of Diamonds and other jewelry who operate without the benefit or cost of maintenance of an office or store.

Pohl diamond. A fine-quality, 287-carat alluvial diamond that was found by Jacobus Jonker (who also found the jonker diamond at the same time and place) in January, 1934, in the Elandsfontein diggings, near Pretoria, Republic of South Af­rica. The stone was cut by Lazare Kaplan for its owner, Harry Winston, New York City gem dealer. The largest stone cut from the rough,


which was reported sold to an opera singer, was an emerald cut that weighed between 40 and 50 carats. Also known as the De Pohl Dia­mond.

point. (1) In weighing Diamonds, one hundredth part of a carat, each one hundredth being called a point; e.g., 32 hundredths (0.32) of a carat is called 32 points, and a diamond weighing 0.32 carat is said to be a 32-point diamond, or a 32-pointer. (2) The sharp end or tip of a pear shape or marquise diamond. See

MARQUISE, PEAR SHAPE.

point cut. Believed to be the earliest form of diamond fashioning, consist­ing of simply polishing the natural faces of an octahedron. Also called diamond point. This cut is no longer used.

Pointe de Bretagne diamond. The

great diamond (weight unrecorded) of the French House of Dunois. Set with hanging ruby drops. Francis I, who initiated the Crown Jewels of France as a permanent collection, wore the diamond and drops in his cap. Further information lacking.

Pointe de Milan. A point-cut dia­mond. Part of the dowry of Catherine de Medici, niece of Pope Clement III, when she married the future King Henry of France in 1533. She gave it to her daughter-in-law, Mary Stuart, afterward Queen of Scotland, who married Francis II of France in 1559. Additional historical details lacking.

 
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