By Russell Shor

The Spring 2008 issue of G&G

The article focuses on Mozambique, which has produced such tourmalines since 2001, though only in 2005 did that fact become widely known. The study presents extensive analyses, which conclude that the Mozambique goods, like similarly colored tourmaline from Brazil and Nigeria, contain trace amounts of copper.

Written by G&G editor Brendan Laurs and a team of co-authors, this article also reports that production of Mozambique tourmaline is certain to increase after mechanized mining operations begin later this year.

Winter 2007 Issue
The Winter 2007 issue of G&G features the most up-to-date look at synthetic diamonds created by the chemical vapor deposition (CVD) method.

A new generation of synthetic diamonds from Apollo Diamond Inc., now in the early stages of commercial marketing, shows significant improvements in size, color and clarity over samples analyzed in G&G's Winter 2003 issue. GIA researchers Wuyi Wang, Matt Hall, Kyaw Soe Moe and Tom Moses, in conjunction with Apollo Senior Scientist Joshua Tower, analyze the gemological properties of the latest Apollo CVD synthetics and their identifying characteristics.

A second article details the vivid yellow manganese-rich tourmaline found in the Lundazi district of Zambia. Mined since the early 1980s, the deposit mostly produces melee-size material, though larger pieces do turn up. Brendan Laurs, William Simmons, George Rossman, Eric Fritz, John Koivula, Björn Anckar and Alexander Falster offer a detailed overview of the mining activities on the basis of an on-site visit and extensive analysis of the area's gem production.

The fluorescence of colored diamonds and the potential of a relatively low-cost mobile fluorescence spectrometer for characterizing colored diamonds is the subject of a third article. Researchers Sally Eaton-Magaña, Jeffrey Post, Peter Heaney, Roy Walters, Christopher Breeding and James Butler provide fluorescence results for 72 diamonds of various fancy colors, 62 of them naturally colored. The study found that, based on their fluorescence spectra, nearly all of the natural-color diamonds could be grouped into three categories that correspond to their body color. A spectrum that is not consistent with a diamond's body color may indicate that the stone has been treated.

The Winter issue cover story examines an important diamond necklace presented by Napoleon Bonaparte to his second wife, Marie-Louise of Austria, Empress of France, in 1811. Tests showed that most of the larger stones among the 234 diamonds are the relatively rare type IIa, while a majority of the smaller ones are type IaAB. The article also traces the history of the necklace from Napoleon's time to its donation to the Smithsonian by Marjorie Merriweather Post in 1962.

Lab Notes
• In the Lab Notes section, researchers from both the Carlsbad and New York Laboratories detail several unusual diamonds they examined recently. A 1.01-ct. type IIa E-color diamond displayed a photoluminescence feature that previously had been seen only in certain type I diamonds, which typically contain nitrogen but may also contain nickel. Such bands can be important in determining whether or not a diamond is treated.

• Another 1.01-ct. diamond contained two well-formed crystal inclusions – one bluish-green and the other reddish-orange – that inspired its nickname, the "Christmas stone." Tests determined that the orange inclusion was garnet, while the bluish-green crystal was omphacite.

• Two diamonds, one a 0.57-ct. Fancy Deep brownish-yellow and the other a 3.06-ct. natural black, displayed unusual etch channels. The yellow diamond had multiple channels naturally filled with a transparent material that was completely surrounded by a dark brown material. The black diamond had a long, surface-reaching etch channel that was aligned perfectly with the growth direction.

• Other interesting items seen by the Labs include a large Buddha, standing 6.3 inches tall and weighing 2,620.7 carats, carved from a single emerald crystal; a 3.78-ct. light gray-blue sapphire with a double star; a 10.45-millimeter bead that proved to be gold-coated onyx; and a triangular bead that appeared to be turquoise, but was actually impregnated glass.

Gem News International
Gem News International reports on the record auction prices, more than $1 million per carat, recently achieved by several fancy-color diamonds; an update on Namibian diamond mining operations; and a new source for andradite in Pakistan. Finds of rare stones include axinite in Tanzania, baddeleyite in Myanmar, chrysocolla chalcedony in the border region between Iran and Armenia, yellow-green clinohumite and yellow chondrodite in Tanzania and transparent dumortierite and sapphirine in Tanzania.