gems, jade, nephrite, jadeite, fei cui, Chinese jade carving

Sinkankas: Introduced with a brief history of Chinese jade and the development of carving into the 19th century. Objects include mountains, animals, human figures, vessels, plaques, wands, etc., each depicted and described with dates and dimensions. Handsome catalog of unusual format. Comment by Born, 169.

corundum, Afghanistan.12, Tajikistan.12, spinel, gems, balas ruby, lapis lazuli, Badakhshan

H.A.R. Gibb’s annotated English translation presents Ibn Battuta’s fourteenth-century account of travel through the Islamic world and beyond. Volume 3 follows his journeys through Central Asia, Afghanistan and northern India, including his service at the court of Sultan Muhammad ibn Tughluq in Delhi. Descriptions of towns, religious institutions, commerce and court ceremonial combine personal observations with historical anecdotes and information obtained from others. Of particular gemological interest is the passage on p. 571, where Ibn Battuta describes the ruined city of Balkh and its surviving architectural inscriptions decorated with lapis-blue pigment. He corrects the common attribution of lapis lazuli to Khurasan, explaining that it actually comes from the mountains of Badakhshan. He also connects that region’s name with the gemstone called badakhshi, popularly pronounced balakhshi, providing evidence for the geographical origin of the historical name “balas ruby,” associated with red spinel. Gibb’s accompanying notes locate the lapis lazuli mines in the upper Kokcha valley and compare the passage with Marco Polo’s descriptions of lapis lazuli and balas rubies. The passage documents medieval knowledge of gemstone sources and terminology, without claiming a personal visit to the mines.

corundum, ruby, sapphire, quality.10, gems

The old Palace of the Sultans of the Ottoman Empire stands on a promontory in the city of Istanbul. It is built high above the Bosphorus with a view across to Asia just over one mile away. Istanbul has been on the trade route between East and West throughout the centuries so that some of the choicest silks, jewels, gold, silver and porcelain reached the city. The Palace is really a series of pavilions built by successive Sultans around inner courtyards, cooled by many fountains and surrounded by high walls. Here the Sultans lived in the hey-day of the Ottoman Empire. Originally in the 15th Century, the Treasury was housed in seven towers guarded by 250 Janissaries. The first four towers contained precious jewels, gold coins were consigned to the fifth, whilst the sixth was filled with silver coins. The seventh was reserved for government documents. Sultan Murat III moved the Treasury to seven large rooms in the Palace; and a record taken in the 18th Century showed that it contained 199,371 jewels. Over the years each Sultan added more to the Treasury and when the last Sultan was deposed in 1919, by Kemal Ataturk, the Palace was turned into a museum, so that the treasures have remained intact.

corundum, treatments.6 dyed corundum, gems

gems, topaz, causes of color, spectroscopy

Bank discusses the causes of color in topaz and the changes that may be produced by natural or artificial influences. He examines the behavior of differently colored topaz and considers the effects of irradiation and subsequent heating on color, including the production, alteration, and loss of color centers within the crystal. The paper relates these changes to the structural and chemical characteristics of topaz and discusses their significance for understanding naturally occurring colors as well as artificially induced coloration. The study is of gemological importance in demonstrating that topaz color may be unstable or modified by treatment and that observed color does not necessarily represent the original state of the material.

gems, garnet, pyrope-almandine, rhodolite, Macon County, North Carolina, North America

It is well known that a whole series of garnets exists from pyrope to almandine, due to the isomorphous replacement of Fe for Mg in the basic chemical composition, and for those lying near the middle of the series Anderson has proposed the name “pyrandine”. It is not so well known that a distinct subvariety of the series is recognized which, because of its rose-red to pale violet colour, has been named “rhodolite” (Gr. rhodon, a rose). It is a rare stone and many gemmologists may not have encountered a specimen. According to Phillips, this variety was found, in limited quantity, in Cowee Valley, Macon County, North Carolina. However, a few other sources are known and Sinkankas reports that fine quality material of unprecedented size has recently appeared from Tanzania. Very occasionally, stones having the colour described for rhodolite are encountered, but carrying no qualification other than “garnet”. It seems that there is some reluctance to apply the term “rhodolite” unless it is known that the stone originated from Macon County. If, however, a garnet possesses physical features, in addition to colour, which mark it as a distinctive entity within the pyrope-almandine series, it seems only reasonable that it be granted its status and accorded its value, irrespective of its source. Rhodolite is a subvariety near to pyrope and Webster notes that its composition lies between pyrope and almandine in the ratio of 2:1. The constants for pyrope show a considerable range and the figures given by different authors do not exactly correspond, particularly in the upper limits. This is not surprising, since one is reaching the intermediate (“pyrandine”) type. Phillips states the R.I. range to be from 1.730 to 1.751, but Anderson gives 1.76 as the upper limit and Webster records 1.77. It is perhaps rather curious that the R.I. of rhodolite, which belongs to this series, has only the single figure of 1.76 recorded against it. The same applies to the S.G.; Phillips gives a range of 3.65 to 3.82 for pyrope and other authors quote similarly, yet the single figure of 3.84 is given for rhodolite. Apart from these two constants, the only definite information recorded in standard works is that rhodolite shows the absorption bands characteristic of the almandine spectrum.

corundum, synthetic corundum.7, gems

corundum, history.1, India.12, gems, Indian lapidary

corundum, history.1, Sri Lanka.12, Thailand.12, China.12, gems

Ma Huan’s account of countries encountered during three of Zheng He’s early fifteenth-century maritime expeditions describes ports, rulers, religious practices, customs, natural products, and commercial exchange across Southeast Asia and the Indian Ocean. J.V.G. Mills’s translation, based on Feng Ch’eng-Chün’s edited Chinese text, supplements the narrative with an extensive historical introduction, annotations, maps, and appendices on navigation and geographical identification. Of particular gemological interest is the description of Ceylon, where red, blue, and yellow stones termed ya-ku are identified in the commentary as ruby and blue and yellow sapphire. Ma Huan describes collecting gemstones from sand exposed or carried down by heavy rain and records the belief that gems were the crystallized tears of Buddha. His account also describes royal supervision of pearl recovery, with oysters left to decay before the pearls were washed out and delivered to officials, although some pearls were stolen and sold abroad. The Calicut section provides unusually detailed evidence of trading procedures: brokers and officials established exchange terms by a formal handclasp, after which merchants brought precious stones, pearls, and coral for examination and prolonged price negotiation. It also records customs collection and a jeweled gold girdle sent as tribute to China. These passages place gems within interconnected systems of local production, merchant exchange, royal revenue, religious belief, and diplomatic gift-giving, making the work an important early source for the history of Asian gemstone commerce.

corundum, treatments.6, gems