gems, lapis lazuli, Afghanistan, history of gemology, gem trade, Central Asia, trade routes

The splendid jewelry of lapis lazuli found throughout the ancient East fully deserves the rich epithets authors have lavished on it since antiquity. Artifacts of lapis lazuli provide evidence for the history of art. Their wide distribution and the fact that there are only a limited number of deposits where lapis lazuli can be mined present realistic prospects for determining ancient trade routes and cultural ties in the East. This article is devoted to an examination of the trade routes leading from the deposits of lapis lazuli in Badakhshan in northern Afghanistan.

gems, ancient gems, glyptic, archaeology, archaeogemology, Ethiopia, Red Sea, Eritrea, olivine basalts, geology, analytical

The island of Kod Ali is a small diatreme cone lying close to the Ethiopian coast at latitude 13° 57′ N, longitude 41° 49′ E. This volcanic structure, produced by geologically Recent volcanic activity, consists, almost entirely, of pyroclastic debris. Evidence of a liquid phase is confined to the thin veneers of markedly alkalic olivine basalt which coat many of the abundant gabbroic, pyroxenitic and lherzolitic fragments found on the island. As silicic inclusions are completely absent and as the alkalic liquid phase and the “tholeiitic” inclusions are seemingly genetically unrelated, it is proposed that the latter might have been derived from a tholeiitic plutonic layered sequence that underlies the tholeiitic basalts of an “oceanic” Red Sea floor.

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

Sinkankas: A work perhaps less remarkable for its cataloguing of about 200 examples in the museum collection than for its discerning commentary. Here it is revealed that the author wrote from observations made while cataloguing more than 600 pieces in the collection, assembled between 1919 and 1969 and now numbering over 1,000 objects. Among these is a suite of Eastern Zhou jades dating from the fifth to third centuries BC, derived from the Bishop White Collection and discussed in part in his Tombs of Old Loyang (Shanghai, 1934). Many of the pieces illustrated in the present work, however, had never previously been published. Dohrenwend provides an excellent discussion of the problems associated with jade studies, namely correct mineralogical identification, dating, and answering the question, “Are these Chinese jades?” Another valuable contribution is his study of tool marks on jade objects as evidence of manufacturing techniques characteristic of particular periods, thereby improving the accuracy of dating. A further interesting section reviews the pioneering contributions to jade studies by scholars such as Laufer, Salmony, Willetts, Pelliot, and Hansford, together with a special discussion of Chinese documentary sources. The final part of the text examines the various types and classes of jade objects, whether ceremonial or utilitarian. The catalogue entries are exceptionally detailed, although in many instances photographs of light-coloured jades do not contrast well against the white paper background, making details difficult to discern. Includes an extensive and useful bibliography. Reviewed in Journal of Gemmology 13(3), 1972, pp. 111–112; also discussed in Born, pp. 115–117.

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, synthetic corundum.7, gems