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Pyrope PYc-17 - History

Pyrope PYc-17 - History


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Pyrope

(PYc-17: dp. 490; 1. 156'4" b. 24'7", dr. 13'2"; s. 12.5 k.;
a. 1 3", 1 iOmm., 2 dct.)

Pyrope (ax-Oceania) was built by Germania Werft., Kiel Germany in 1923, purchased from Fred Perry, 15 December 1941; renamed Pyrope (PYc-17), 27 December 1941, converted by the Martinolich Shipbuilding Co., and commissioned 11 March 1942, Lt. (j.g.) John A. Gorham in command.

Assigned to the Hawaiian Sea Frontier, Pyrope departed San Diego 21 April 1942 and arrived at Pearl Harbor l May. For the next three years, she patrolled in the Hawaiian Islands and on 1 April 1945 steamed west, to Midway, whence she operated until August. Designated for inactivation on her return to Pearl Harbor. she departed Hawaii for the west coast 28 September. Arriving at San Diego 8 October, she decommissioned 14 December 1945, was struck from the Navy List 8 January 1946; and was sold to Juan Perlo Los Angeles, 29 January 1947.


Pyrope PYc-17 - History

All these Garnets are members of the Isomophoros series of Garnets. Pyrope has a blood red color with few inclusions. Almandite Garnet is deep red to violet and can show asterism. Exceptionally beautiful Pyrope/Almandine Garnet the color of fine French Claret wine comes from Mozambique and is known as ‘Mozambique Garnet.’ This has become highly prized when it looks very beautiful. Rhodolite Garnet is a combination of pyrope and almandine and is a red to reddish pink and violet also called ‘grape garnet’. This is the superior variety of Isomophoros Garnet as it is far brighter.


Biography

Early life

Little is known about Pyrope's past. However, at one point in time, he was enrolled in Mixopolis Middle School.

First Adventures

Pyrope was first seen in the Mixing 101 classroom, picking on Camillot and Mixadel. He was later seen in the Mixopolis Middle School gym on Camillot's blue team during a game of Murpball. He was also seen on a field trip to the Mixopolis Zoo and later Mixed with everyone to defeat the Mixeloptors. ("Every Knight Has Its Day")

Pyrope was among the many Mixels that was Nixed on the day of the I-Cubit scam. He later appeared celebrating the Mixels' victory. ("Nixel, Nixel, Go Away")


Garnet History and Lore

Antique Pyrope Hairpin in the collection of the Smithsonian National Museum of Natural History - Chip Clark, courtesy Smithsonian Institution Thousands of years ago, red garnet necklaces adorned the necks of Egypt&rsquos pharaohs, and were entombed with their mummified corpses as prized possessions for the afterlife. In ancient Rome, signet rings with carved garnets were used to stamp the wax that secured important documents.

The term carbuncle was often used in ancient times to refer to red garnets, although it was used for almost any red stone. Carbuncle was thought to be one of the four precious stones given to King Solomon by God.

Centuries later, in Roman scholar Pliny&rsquos time (23 to 79 AD), red garnets were among the most widely traded gems. In the Middle Ages (about 475 to 1450 AD), red garnet was favored by clergy and nobility.

Red garnet&rsquos availability increased with the discovery of the famous Bohemian garnet deposits in central Europe around 1500. This source became the nucleus of a regional jewelry industry that reached its peak in the late 1800s.


Historical Reading List: Red Pyrope Garnets from Bohemia

This antique hair comb set with Bohemian pyrope garnets from the Czech Republic is part of the National Gem Collection at the Smithsonian Institution. Courtesy: Chip Clark, Smithsonian Institution

The Čéske Středohoří highlands of central Bohemia in the Czech Republic have been the source of gem-quality red pyrope garnets for hundreds of years. The region is located about 60 km northwest of Prague. Mining of garnets began in the area in the 16 th century, although early European jewelry created a millennium earlier has been found to contain this material. Rock breccias resulting from volcanic eruptions are thought to have been the host of the garnets &ndash these breccias contain fragments of a mantle rock called peridotite (here altered and serpentinized), which appears to have been the original source of the garnet. The pyrope crystals, typically in sizes up to about 6 mm in diameter, is generally recovered as loose grains from sediments that are spread over a large area. The garnets are separated by washing these sediments. At times in the past, vertical shafts were also constructed to access to the garnet rock underground. Much of the garnet production is manufactured for jewelry use in this same area of the country. Bohemian garnet jewelry was especially popular in the 19 th century, and is still valued today.

HOW TO USE THIS READING LIST

This reading list was compiled to give you an opportunity to learn more about the history of red pyrope garnets from Bohemia. A number of the articles were published in the 1800s and early 1900s &ndash when many classical gem deposits of historical importance were discovered &ndash and gemology and mineralogy became sciences. The list is presented in chronological order to emphasize the development of ideas over time. The list is not comprehensive, but a compilation of the some interesting gemological information that has often been forgotten or overlooked.

Many of the articles exist in the public domain and can be found online at digital libraries such as Hathitrust, Internet Archive, or other digital repositories. More recent publications can often be found in libraries, including the Richard T. Liddicoat Gemological Library. Abstracts of these articles can usually be found on the website of the original journal or magazine, and the article itself is often available for purchase from the publisher.

Regarding the GIA library&rsquos holdings and on-site access, please contact the GIA library in Carlsbad.

Garnets from Bohemia were mentioned by Georgius Agricola, the &ldquofather of mineralogy&rdquo, in his 1546 work De Natura Fossilisum (Textbook of Mineralogy).

Chemische Untersuchung der Böhmischen Granats [Chemical Examination of Bohemian Garnets], F.K. Achard, Neue Philosophische Abhandlungen der Baierschen Akademie der Wissenschaften, Vol. 1, pp. 282-325, (1778). An early study of the chemical composition of Bohemian garnets.

Oryctographie der Gegend von Bilin [Fossils and Minerals from the Area of Bilina], F.A. Reuss, Abhandlungen der Böhmischen Gesellschaft der Wissenschaften, pp. 58-74, (1788). An early description of pyrope garnet from an area of Bohemia.

Granaten [Garnets], J.G. Krünitz, Oekonomische&ndashTechnologische Encyclopadie, Vol. 19, pp. 702-708, (1788). An entry on garnets from an early encyclopedia.

Granaten [Garnets], Unknown author, Deutsche Encyclopadie, Vol. 13, pp. 221-224, (1788). An entry on garnets from an early encyclopedia.

Granat-Steine [Garnet Rock], Unknown author, Salzburger Intelligenzblatt, No. 42, Columns 683-685, (1792). A brief description of garnets from Bohemia.

Chemische Untersuchung des Böhmischen Granats [Chemical Examination of Bohemian Garnets], M.H. Klaproth, Beiträge zur Chemischen Kenntnis der Mineralkorper, Vol. 2, pp. 16-21, (1797). An early study of pyrope undertaken by a famous chemist.

[Bohemian Gemstones], J.A. Demian, Darstellung der Oesterreicheischen Monarchie nach den Neuesten Statistischen Beziehungen, pp. 62-62, (1804). This book contains a short section on garnet and other gemstones from Bohemia.

Undersökning af Pyropen från Meronitz [Examination of Pyrope from Meronitz], H.G.T. Wachtmeister, Kungliga Svenska Vetenskapsakademiens Handlingar, Vol 13, pp. 216-223, (1825). An early chemical analysis of Bohemian pyrope.

Analyse des Pyrop&rsquos vom Stifelberge in Böhmen [Analysis of Pyrope from the Stifelberge in Bohemia], F. von Kobell, Archiv für die Gesammte Naturlehre, Vol. 8, pp. 447-454, (1826). The author provides a quantitative chemical analysis of pyrope.

[Bohemian Garnet], K.M. von Sternberg, Monatschrift der Gesellschaft des Vaterländischen Museums in Böhmen, Vol. 1, (May), pp. 62-67, (1827). A description of the garnet deposits is presented.

Böhmens Edelsteine [Bohemian Gemstones], F.X.M. Zippe, Abhandlungen der Königlichen Böhmischen Gesellschaft der Wissenschaften, Vol. 4, pp. 21-54, (1837). A summary description is presented of Bohemian gem minerals including pyrope. The article was summarized in the Verhandlungen der Gesellschaft des Vaterländischen Museums in Böhmen, pp. 31-47, (1838), Neues Jahrbuch für Mineralogie, Geognosie, Geologie und Petrefaktenkunde, Vol. 12, pp. 67-69, (1844) and in the Berg- und Hüttenmännische Zeitung, Vol. 3, No. 13, pp. 284-286, (1844).

Ueber das Vorkommen des Pyrops in Böhmen [On the Occurrence of Pyrope in Bohemia], A.E. Reuss, Archiv für Mineralogie, Geognosie, Bergbau und Hüttenkunde, Vol. 11, pp. 298-314, (1838). The author describes the pyrope occurrence. This article is summarized in the Neues Jahrbuch für Mineralogie, Geognosie, Geologie und Petrefaktenkunde, Vol. 7, pp. 97-100, (1839).

Pyropenlager von Meronitz [Pyrope Deposits at Meronitz], A.E. Reuss, Geognostische Skizzen aus Böhmen, Vol. 1, pp. 155-161, (1844). The garnet deposits near this town are described. Another article on this deposit by the same author entitled Der Pyrop von Meronitz und seine Begleiter [The Pyrope of Meronitz and its Companions] appeared in Lotos, Vol. 2, pp. 214-223, (1852)

Die Granatenindustrie zu Waldkirch [The Garnet Industry in Waldkirch], J. Betz, Badisches Centralblatt für Staats- und Gemeinde-Interessen, Vol. 5, pp. 85-87, (1859). The polishing of Bohemian garnets in the town of Waldkirch is described.

Die Bearbeitung der Granaten im Schwarzwald [The Working of Garnets in the Black Forest], F.A. Walchner, Westermann&rsquos Jahrbuch, Vol. 11, No. 63, pp. 336-342, (1861). The author describes the manufacturing of gem garnets found in southeastern Germany and Bohemia.

Diamant-Entdeckung in den Böhmischen Pyrop-Lagerstätten [Diamond Discovery in the Bohemian Pyrope Deposit], Unknown author, Das Ausland, Vol. 43, No. 7, pp. 166-167, (1870). A brief report on the discovery of diamonds in the pyrope locality.

Ueber das Muttergestein der Böhmischen Pyropen [The Mother Rock of the Bohemian Pyrope], C. Doelter, Tschermak&rsquos Mineralogische Mittheilungen, No. 1, pp. 13-18, (1873). The author identifies the source rock of the pyrope garnet as serpentine today the rock is recognized as an altered (serpentinized) peridotite, an olivine-rich rock that originates in the earth&rsquos mantle.

Die Granatenschleiferei im Breisgau [Garnet Polishing in Breisgau], O. von Eisengrein, Jahresheft des Breisgau-Geschichtsvereins Schauinsland, Vol. 5, pp. 29-36, (1878). The garnet polishing industry in the town of Breisgau in Baden is described.

O Horninách Pyrop Sprovázejícíh v Čéske Středohoří [On Pyrope and Associated Minerals of the Bohemian Central Highlands], C. Zahálka, Sitzungsberichte der Koniglich-Bohmischen Gesellschaft der Wissenschaften in Prag, pp. 461-475, (1884). A description of the pyrope occurrences is provided.

Böhmische Granaten [Bohemian Garnets], T. Gampe, Die Gartenlaube, Vol. 41, No. 7, pp. 107-110, (1893). The author discusses the pyrope mining and manufacturing industry in Bohemia.

Bohemian Garnets, G.F. Kunz, Transactions of the American Institute of Mining Engineers, Vol. 21, pp. 241-250, (1893). The garnet-producing district near Prague is described.

Bohemian Garnets, J.B. Hawes, Reports from the Consuls of the United States, Vol. 42, No. 153, pp. 205-207, (1893). A brief report is given by the consul in Prague of the situation for mining and manufacturing gem garnets. This report is summarized in the Journal of the Society of Arts, Vol. 41, No. 2127, pp. 875-876, (1893).

Edelsteinkunde [Precious Stones], M. Bauer, C.H. Tauchnitz, Leipzig, (1896). This gemological textbook contains a section on Bohemian pyrope on pages 405-409.

Die Böhmischen Granatlagerstätten und die Edelsteinseife des Sufzergründels bei Hinterhermsdorf in Sachsen [The Bohemian Garnet Deposit Sites and the Gemstone Alluvial Deposits of the Sufzergründel near Hinterhermsdorf in Saxony], H. Oehmichen, Zeitschrift für Praktische Geologie, Vol. 8, (January), pp. 1-17, (1900). The author provides a detailed description of the Bohemian garnet occurrences, and of the alluvial gem deposits in neighboring Saxony.

Chemische und Mineralogische Studien am Granat [Chemical and Mineralogical Studies of Garnets], M. Seebach, Karl Rössler Buckdruckerei, Heidelberg, (1906). This book contains a chapter on pages 30-37 on Bohemian pyrope.

Die Granatschleiferei in Harmersbach und Waldkirch [Garnet Polishing in Harmersbach and Waldkirch], K. Bittmann, Hausindustrie und Heimarbeit im Grossherzogtum Baden zu Aufang des XX Jahrhuderts, pp. 7-19, (1907). In the 19 th century, Bohemian garnets were polished for jewelry purposes in various locations including these two towns in the Baden region of Germany.

Mineralogische Skizzen &ndash Böhmische Granaten [Mineralogical Sketches &ndash Bohemian Garnet], W. Peiter, Aus der Heimat, Vol. 22, No. 1, pp. 17-18, (1909). A brief description is given of the garnet occurrences.

Die &ldquoBöhmischen&rdquo Granaten [Bohemian Garnets], B.R. Müller, Wirtschafts-Geologie der Tschechoslowakischen Republik, (1921). This book contains a short section on the garnets (pp. 142-145).

Ložiska Pyropů v Čéske Středohoří [Pyrope Localities of the Central Bohemia Highlands], L. Sýkora, Geotechnica, Vol. 14, pp. 1-16. (1952). The author reviews pyrope localities.

Bohemian Garnet &ndash Today, J. Schlüter and W. Weitschat, Gems & Gemology, Vol. 27, No. 3, pp. 168-173, (1991). The current situation of pyrope garnet mining in the Bohemian hills is summarized.

La Bohème, Petr Korbel, Lapidary Journal, Vol. 46, No. 10, pp. 46-51, (1993). The history of garnet mining and manufacturing centered near the Bohemian city of Turnov are discussed.

Mineralogy of the Louvres Merovingian Garnet Cloisonné Jewelry: Origins of the Gems of the First Kings of France, F. Farges, American Mineralogist, Vol. 83, No. 3/4, pp. 323&ndash330, (1998). Based on a study and chemical analysis of early European garnet jewelry, the author identified some of the material as having come from Bohemia.

Mittelalterliche Edelsteinschleifereien in Südwestdeutschland und ihre Rohstoffe [Medieval Gemstone Lapidaries in Southwestern Germany and their Sources of Raw Materials], I. Baranyi, Carolinea, Vol. 59, pp. 15-23, (2001). Medieval lapidary facilities for pyrope and gemstone polishing are described from several areas of Baden in Germany.

Bohemian Garnet, A.V. Seifert and S. Vrána, Bulletin of Geosciences, Vol. 80, No. 2, pp. 113-124, (2005). The authors present the results of a chemical analysis of the garnets, and they discuss the geological setting of the garnet occurrence.

Mineral inclusions in Pyrope from Garnet Peridotites, Kolín area, central Czech Republic, S. Vrána, Journal of Geosciences, Vol. 53, pp. 17-30, (2008). A description is given of typical mineral inclusions found in Bohemian garnet.

The Fiery-Eyed Volcanoes of Bohemia, J. Kouřrimský and J. Hyr&scaronl, in H.A. Gilg and others, Editors, Garnet &ndash Great Balls of Fire, Lithographie LLC, East Hampton, Connecticut, pp. 56-59, (2008). The authors describe the occurrence, and historic mining and manufacturing of Bohemian pyrope for jewelry use.

The History of Pyrope Extraction and Processing in the Czech Republic and Its Significance for Geotourism, M. Duraj, M. Marschalko, R. Duda, D. Sitányiová, and S. Masarovičová, Procedia Earth and Planetary Science, Vol. 15, pp. 663-668, (2015). The history of pyrope extraction and manufacturing for gem purposes in Bohemia is discussed.

Dr. James Shigley is a distinguished research fellow at the Gemological Institute of America in Carlsbad, California.


Varieties

Rhodolite

Rhodolite is the purple variety of pyrope-almandine. The name and color come from the flower of the rhodondendron.
The jewelry trade sometimes describes every purple garnet as a rhodolite but it should be reserved only for those having an intermediate chemical composition between pyrope and almandine.

Inclusions

85X Magnification
©Jamey Swisher

Malaia

Malaia garnet (or malaya) is the red-orange variety of pyrope-spessartite discovered in the 1970's in Kenia as a by product of rhodolite.
The name is derived from the Swahili word for prostitute (which freely translates to "outcast" or "out of the family") [see: Swahili - English Dictionary Rouse, 1986].


Xolmis pyrope (von Kittlitz, 1830)

(Tyrannidae Ϯ White Monjita X. irupero) I cannot find this name in my dictionaries, and David & Gosselin 2002b, list it as a word of unknown origin. It may be a misreading of “Xomotl” of Hernandez 1651: “De Xomotl . Avis est dorso et alis desuper nigris, ac pectore fusco” (Aztec Xomotl waterbird, perhaps some sort of duck), or perhaps be based on an unrecorded Güaraní name (although not found under “Pepoaza” in de Azara 1802-1805, nos. 201, 202, 203) "X. Fam. Muscicapiadae Vigors. Muscicapa Lin. 2 . 2 Ferner könnten als Gattungen abgesondert werden: Knipolegus für Musc. lophotes Tem. und cyaneirostris Vieill. Az. 181 die Peposaza [sic] Az. (Xolmis), die sich in der Lebensweise den Arten der Gattung Oenanthe nähern und die Queues-rares (Xenurus) desselben. Alle hieher zu stellende Vögel zeichnen sich durch rauhe Stimme und die Gewohnheit aus, auf zweyflüglige Insecten zu lauren, und dieselben im Fluge zu haschen. Sie fitzen vorzugsweise auf dürren Zweigen und Aesten" (Boie 1826) "Gattung Xolmis 2 Pepoazo Azar. Hieher aus America: 1. Muscicapa moesta Lichst. Az. [= X. irupero] 2. — vittigera Lichst. Azar. [= X. coronata] 3. — mystacalis Spix tab. 31. [= Fluvicola nengeta] 4. — velata Lichst. [= X. velata] 5. — bicolor Gm. [= Fluvicola pica] Die Lebensweise dieser weiß und schwarz gefärbten Vögel nähert sich der der Steinschmätzer (Vitiflora Briss.), an die sie sich auch durch die Vertheilung der Farben ihres Gefieders anschließen. . 2 . Ξολμις, Isis 1826 S. 975." (Boie 1828) "Xolmis Boie, 1826, Isis von Oken, col. 973 based on "die Pepoasza" [= Las Pepoazás] of Azara, 1805, Apuntamientos Hist. Nat. Páxaros Paraguay Rio Plata, 2, pp. 164-175. Type, by subsequent designation (Sclater, 1888, Cat. Birds, Brit. Mus., 14, p. 10) 1 , T[aenioptera] irupero (Vieillot) = Tyrannus irupero Vieillot. . 1 G. R. Gray (1840, List Genera Birds, p. 29) proposed "X[olmis] Nengeta (L.)" as type of Xolmis, but that species was not one of the six species included by Azara in his "Pepoazás," the sole basis of Boie's name Xolmis. Later, Boie (1828 Isis von Oken, col. 318) again used the name Xolmis, this time for five species, only three of which were among the original six. This time Boie quoted binomial names (taken from earlier authors) and by doing so he restricted the possible candidates for selection as types of the genus to these three." (Traylor in Peters 1979, VIII, 162).
Var. Xolmus.
Synon. Hemipenthica, Heteroxolmis, Hydrozetetes, Nengetus, Orsipus, Pepoaza, Pyrope, Taenioptera.

(syn. Xolmis Ϯ Fire-eyed Diucón X. pyrope) Gr. &pi&upsilon&rho&omega&pi&eta&sigmaf purōpēs fiery-eyed < &pi&upsilon&rho pur, &pi&upsilon&rho&omicron&sigmaf puros fire &omega&psi ōps, &omega&pi&omicron&sigmaf ōpos eye "Augenstern prächtig feuerfarben" (von Kittlitz 1830) "Gen. PYROPE *) nov. gen. &mdash Feueraug-Pepoaza. 163. 1. P. Kittlitzi Nob. Muscicapa pyrope Kittl. Ein. Vög. Chil. p. 19. t. 10. &mdash Pepoaza pyrope Orb. & Lafr. Syn. p. 63. 6. &mdash Orb. Voy. p. 348. 272. &mdash Xolmis pyrope Gray Voy. Beagl. p. 55. &mdash Taenioptera pyrope Id. Gen. B. I. p. 241. 7. . *) Von &pi&upsilon&rho&omega&pi&omicron&sigmaf (feueräugig). Es erinnert diese Gattung schon mehr an die kleinern Tyrannen, die Färbung ist einfarbiger, die Flügel sind ohne Binden, verhältnissmässig kürzer und mit kürzerer erster und zweiter Schwinge, als bei den eigentlichen Taeniopterae." (Cabanis & Heine 1859) "Pyrope Cabanis and Heine, 1859, Mus. Heineanum, 2, p. 45. Type, by monotypy, P. kittlitzi Cabanis and Heine = Muscicapa pyrope Kittlitz." (Traylor in Peters 1979, VIII, 162).


COVID Update 5/27/2021

For all fully vaccinated members and guests the club house, pavilion and general grounds shall return to normal, pre COVID-19, access and congregation rules. Anyone not vaccinated should continue to follow previously established mask and distancing guidelines. Vaccination status will be per the honor system. Those who choose to continue wearing masks and distancing should be respected by others. This will be effective immediately. Regards,Fred BertoniCommodore


Garnet

The term garnet applies to a group of minerals with six main varieties. The varieties differ in chemical composition and color but share the same crystal system. These varieties are:

While most people think of garnets as red, it occurs they almost every color. The rarest is blue. Garnets are can be found throughout the world. The United States, Brazil, Canada, Germany, Russia, Madagascar, Tanzania, Kenya, and India have produced abundant amounts.

A BRIEF HISTORY OF GARNET

Garnets have been widely known for thousands of years and are found in jewelry from ancient Egyptian, Greek, and Roman eras. The Greeks called garnets “nuktalopos” meaning “lamp stone”. They believed that wearing a garnet around the neck gave one the ability to see in the dark.

Georgian Garnet Fringe Necklace.

​Noah, it is reported in one biblical legend, used a lantern made from garnets in order to safely steer his Ark through the darkness of the night. Cabochon cut garnets have been very important in Christianity, often used to represent Christ’s passion and martyrdom.

During the Middle ages, garnets were used to protect against the plague, eliminate sadness, and prevent evil thoughts. And when hung around the neck, garnets were a sure cure for indigestion and sore throats.

Garnet is the birthstone for January and the gem to commemorate the 2nd Anniversary.

THE METAPHYSICAL ASPECTS OF GARNET

Garnet helps with motivation and is known as the stone for a successful business. It makes a wonderful executive gem, particularly for women.

In addition, garnets foster passion and courage. They help stimulate devotion to your family and friends, while also helping to focus on goals. Garnet can stimulate the senses, and increase your stamina and vitality.

It is a gem of the base chakra and awakens the Kundalini.

MEET THE FAMILY

Astutely observed by Mab Wilson, author of Gems:

Most of us, having been brainwashed by the dark and depressing parures of the turn of the century, forget the many beautiful colors garnets can have. Badly cut, a garnet can indeed be a melancholy object, lugubriously red and usually in a brown study but a clear and well-cut garnet can be bright as a zinnia, as dark as a bottle of red ink, as green as an emerald or the very green of a dew-moistened leaf of the lily of the valley. 1

Georgian/EarlyVictorian Garnet Ring.

Demantoid Garnet Snake Brooch, c.1890.

Victorian Style Spessartine Garnet and Diamond Ring.

Garnets, with their wide range of colors and varieties, have long been an important gem material throughout history with research dating their use back to the earliest known civilisations.

The name garnet is derived from the Latin word granatas, meaning grain or seed. Historically the red varieties of this gemstone, which resemble the seeds of a pomegranate in color, were referred to as garnets. The term garnet has come to refer to the whole family of minerals that crystallize in the cubic system and share the same chemical blueprint. The elements used to fill that blueprint place a gem garnet into one or more of the following:

    : Mg3Al2(SiO4)3 (magnesium aluminum silicate) : Fe3Al2(SiO4)3 (iron aluminum silicate) : Mn3Al2 (SiO4)3 (manganese aluminum silicate) : Ca3Al2(SiO4)3 (calcium aluminum silicate) : Ca3Al2(SiO4)3-x(OH)4x (calcium aluminum silicate with hydroxide) : Ca3Fe2(SiO4)3 (calcium iron silicate)

Pomegranate Seeds
This fruit may have given garnet its name.

Garnet Names

It would have been easy if nature presented us with pure family members but, unfortunately for those trying to classify garnets, this is not the case. The family members listed above represent “end members” within the garnet group. In other words, their composition is an ideal, theoretical one. In reality, all the garnets we use as gem materials are a mix of two or more end members in various ratios. Some of the magnesium which makes a pyrope a pyrope can be replaced by iron or some of the iron that makes an almandine an almandine is replaced by manganese. In gemology, this ‘mixing of end members’ is called isomorphous replacement.

The composition of a garnet determines certain measurable characteristics of the stone such as refractive index and specific gravity. It can also influence the color of the stone, which is why garnets come in many colors and shades. The confusion which occurs from these mixed garnets, together with marketing strategies, has caused an array of trade names to be invented for various garnets. While it is scientifically correct to call the green garnet found in Kenya a green grossular, the gem trade insists on (erroneously) calling it Tsavorite. It sells better that way. Some names are relatively new and are still being contested, others have been in use so long that they have gotten a firm grounding in literature and have been adopted by gemologists. It is important to remember that, at the end of the day, all garnets are a mix of two or more of the end members mentioned above.


Pyrope

Pyrope is a deep yellowish-red garnet that consists of magnesium aluminium silicate and is used as a gemstone. It is a member of the Garnet group and its formula: Mg3Al2(SiO4)3. It is often free of flaws with good transparency, making it an important jewelry gemstone. Pyrope is much rarer than its Almandine counterpart, but it is generally more transparent and has less flaws than Almandine. A well-known environment of Pyrope is kimberlite pipes, where it can be associated together with Diamonds.

The composition of pure pyrope is Mg3Al2(SiO4)3, although typically other elements are present in at least minor proportions these other elements include Ca, Cr, Fe and Mn. Pyrope forms a solid solution series with almandine and spessartine, which are collectively known as the pyralspite garnets (pyrope, almandine, spessartine). Iron and manganese substitute for the magnesium in the pyrope structure. The resultant, mixed composition garnets are defined according to their pyrope-almandine ratio. The semi-precious stone rhodolite is a garnet of

Production and Properties of Pyrope

Pyrope is typically dark red to slightly brownish-red and is considered by some to be the reddest of all the garnets. It is the only member of the garnet family to always display red coloration and it is from this characteristic that it gets its name: from the Greek for fire and eye.

Pyrope is an end-member of a solid solution garnet series with the other end member being alamandite. The chemical composition of Almandite is Fe3Al2(SiO4)3 while Pyrope´s composition is Mg3Al2(SiO4)3 so the only apparent difference is the presence of iron or magnesium. These garnets are gradational in composition and include varying percentages of iron and magnesium. Rhodolite is the mid member of this series and it contains both magnesium and iron. However, the red color is not only related to the basic chemistry and the position in the series, but also to trace amounts of chromium and even grossularite in some cases.

Pyrope is very tricky to distinguish from almandine however it is likely to display fewer flaws and inclusions. Other distinguishing criteria are listed in the adjacent table. Care should be taken when using these properties as many of those listed have been determined from synthetically grown, pure-composition pyrope.

Applications of Pyrope

Garnet was much used as a jewel in ancient times. Anglo-Saxons made adornments of Garnet and gold to accompany them into the afterlife. Pyrope Garnet was considered effective against legendary vampires, and Pyrope bullets were once used in slings in parts of Asia. Bohemia is famous for its Pyrope Garnets, which can be as big as hens’ eggs and were made into lavish jewelry in the 18th and 19th centuries.

It is common in peridotite xenoliths from kimberlite pipes, some of which are diamond-bearing. Pyrope found in association with diamond commonly has a Cr2O3 content of 3-8%, which imparts a distinctive violet to deep purple colouration and because of this is often used as a kimberlite indicator mineral in areas where erosive activity makes pin pointing the origin of the pipe difficult. These varieties are known as chrome-pyrope, or G9/G10 garnets.

Pyrope garnets are also sometimes associated with diamond deposits and it was the findings of pyrope on the surface of the Kalahari Desert and in the alluvial deposits of the Eastern Europe that led to important diamond discoveries in Namibia and Russia. There are no other deposits that have received much notoriety. As most of the pyrope deposits produce dark to over dark stones, there is little interest to extract them and unless some new source of large, beautiful and easy to reach stones become available the production of pyrope will remain limited.


Watch the video: FUSION: Pyrope + Demantoid = Grossular Garnet. Rose Cuarzo (May 2022).