琥珀吧

Copal

In recent years, some jewelry manufacturers have given the name “Caribbean Amber” to an industrially produced green gemstone made from hardened young tree resin, often copal from Colombia.Copal from Colombia is sometimes only a few hundred years old and therefore relatively soft (Mohs 1 – 1.5). But the desired appearance is that of old, transparent green Dominican amber.

柯巴脂

近年来，一些珠宝制造厂把一种由坚硬的年轻树脂（通常是来自哥伦比亚的柯巴脂）经工业生产成的绿色宝石命名为“加勒比海琥珀”。而来自哥伦比亚的柯巴脂有时只有几百年的年龄，因此相对比较软（莫氏硬度1-1.5 [加注:琥珀为2-3]）。却试图表现出年代久远的透明的绿色多米尼加琥珀的（形态）。

Autoclave Process

In the copal hardening process, the resin is wrapped in aluminum foil, then treated in the autoclave for several hours, increasing the temperature, pressure and heating time. The hardened copal lumps are made transparent by placing so-called water settlers in the autoclave. The green color is obtained by adding water at each stage of the process. After the copal has hardened, the aluminum foil is removed and the hardened resin is cut to produce the desired shape (i.e. bead or cabochon). It is then mixed with talcum and heated again in the autoclave. Thereafter, it can be cut and polished to obtain the desired finish.

高压锅处理

在柯巴脂淬火过程中，树脂被包如铝箔，然后在高压锅中处理几个小时，增高温度，压力和受热时间。变硬的柯巴树脂放入高压锅里的“水分转移者”中，使之透明。绿色的获得是通过在每个阶段加入水。在柯巴脂硬化后，铝箔被去掉。硬化后的树脂被切割并生产成预期的形状（如：珠串或者随形宝石）。然后用滑石与之混合，并再次在高压锅内加热。此后，就可以被切割，打磨成最后的完成品。

关于市面上的“加勒比海绿珀”的一些资料文献，来源是美国宝石学协会(GIA)。

CARLSBAD, Calif.– Oct. 20, 2009 – The Fall 2009 issue of Gems & Gemology (G&G), released Oct. 5, looks closely at a treated gem material being marketed as “green amber,” as well as a new gemological test to detect HPHT treatment in type I diamonds.

The publication also offers a crystallographic analysis of the Tavernier Blue diamond, an update on Ammolite mining in Canada, and more.

The lead article, “Characterization of ‘Green Amber’ with Infrared and Nuclear Magnetic Resonance Spectroscopy,” by Dr. Ahmadjan Abduriyim and co-authors, provides an in-depth look at this relatively new material, which is created by treating amber or its much younger counterpart, copal, under heat and pressure. The process artificially “ages” copal and imparts a green to yellow-green color in some samples. The treatment can be detected by characteristic spectral features, but it is not always possible to establish whether the starting material was amber or copal.

“A new treated gem such as ‘green amber’ poses an immediate challenge to the industry for proper identification,” said G&G Editor-in-Chief Alice Keller. “This article greatly enhances our understanding of this attractive product.”

The next article, “A Crystallographic Analysis of the Tavernier Blue Diamond” by Scott D. Sucher, builds on recent research to portray a more accurate model of this historic diamond, a predecessor to the Hope. In “‘Fluorescence Cage’: Visual Identification of HPHT-Treated Type I Diamonds,” Drs. Inga A. Dobrinets and Alexander M. Zaitsev review their discovery of a luminous network of fluorescence at the facet edges and junctions of these treated diamonds. Visible with a fluorescence microscope, this network feature can provide a quick screening method for some HPHT treatment.

Other articles cover ammolite production in Southern Alberta, Canada; polymer-filled aquamarine; the discovery of gem-quality yellow-green haüyne from Tanzania; and aquamarine from northern Italy.

The Lab Notes section features the latest discoveries from the GIA Laboratory, including a treated Fancy red diamond, a useful technique to identify negative crystals in ruby, and a diamond with patterned green radiation stains. Gem News International includes demantoid samples from a new locality at Ambanja, Madagascar, and new rubies from Mozambique, among many other topics.

PDF versions of the Fall 2009 issue are available at http://gia.metapress.com. To purchase a print copy or to subscribe to G&G, visit www.gia.edu/_webapps/gg/orderform/, or email martha.rivera@gia.edu. Call toll-free (800) 421-7250, ext. 7142. From outside the U.S. and Canada, call (760) 603-4000, ext. 7142.