Volume I, Number 4	Carol J. Bova, Editor.    Web Publishing by Doppler FX.	03/01/97

The Eclectic Lapidary is currently undergoing renovation. We'll have new issues soon! INDEX

Amethyst Geodes by Mark Liccini Recently, I received a question about Amethyst Geodes. "I am a NOVICE rock collector - I have always been enamored with AMETHYST GEODES - I like purple and I find geodes exceptionally beautiful. WHAT IS A FAIR PRICE FOR THE FOLLOWING: 1/2 geode approx 18" wide 9" high 18" deep - the interior is a DEEP PURPLE and the piece is intact with no cracks, etc. "This is a large specimen and I was wondering what exactly are the determining factors for price - are geodes like diamonds in that the larger ones are harder to find and harder to keep in one piece?" First, you need to determine the origin of the material. Almost all of these clusters come from near Artigas, Uruguay on the Brazil/Uruguay border, or near Lajeado, Rio Grande Do Sul, Brazil. The other Amethyst producing Areas in Brazil: Minas Gerais, Bahia, Para, Goias, Rhondonia rarely produce Geodes, only plates or loose Crystals. (It's not Bolivian,because a single Bolivian Crystal could be that size.) If the run of the Crystals is 5mm to 15 or so, or all small, it is likely Uruguay. If they are all 10mm and up to even 30-40mm, It is Rio Grande Do Sul. The Uruguay will overall come out much darker than Brazillian. The Brazillian also tends to Zone a lot near the tips. From both areas you will rarely see Geodes sold as specimens -- extra clean, larger size Crystals overall on the matrix. Both areas are supporting large "swing hammer" cobbing operations. As for value,you are asking about two different worlds: for Collection (Specimens) and the hungry Lapidary industry. To begin with, the Crystal you have is not rare by its size. In fact tonnage every month is taken out this size and larger. Many are routinely smashed down to smaller sizes, because the smalls sell quicker, and are easy to handle. Anyway, they first smash up and cobb out the Faceting roughs, separating (Rio Grande Do Sul only) the ones with potential for heating to Gem Citrine.Then they are evaluated piece by piece. Does the Amount of faceting material contained surpass the value that it might bring as a specimen? And it is classified accordingly. This applies only to the darker colors. The medium, light and any poor souls with spotty, therefore low recovery, in dark goods are classified "collection". All included, or pieces recovering only smalls, are also sent to "collection". They are then put up in Bulk and sold $1/kg (lighter colors) to $20/kg in hundreds of kilo to ton lots. Average prices run $10-15/kg. Single fine collection pieces are sold by the "how pretty they are" method, but generally $45-50/kg. (Tubes and other unusual items are in this category.) Overall, large, very clean, extra dark Crystals on a Plate are never sold. The miners cobb them. You can buy in Bulk plates to cobb out smalls for $10/kg and will get the occasional larger one on the plate. The cobbed dark faceting roughs run $500/kg for 1/3 gm extra dark to $10,000/kg for large extra dark color. Mixed of all sizes runs $3,000 to $5,000 per kilo depending on the amount of large. The prices on the best of the Citrine are equal to or even surpass the Amethyst. As Maramba (Para) is finished, and Breziena (Bhia), high quality is scarce. Copyright, 1997 by Mark Liccini Mark Liccini holds degrees from Gemmological Association of Great Britain, and Columbia School of Gemmology, Wash.D.C. .Member: Jewelers Board of Trade, MJSA, AGTA, AGS. Mark Liccini studied Cobbing and mass production techniques in Idar Oberstein, Germany and has an interesting and varied history. He has developed many new Gemstone treatments and mass production gemcutting innovations. Working in Brazil since the mid 1980's, started a Gemstone cobbing factory with 12 men, concentrating on the specialization of rough gemstones only. After spending years in remote areas of Brazil, many without even phones, he discovered the Computer and now has a Gemstone website, a new mail order business, and an extraordinary collection of rough stones.

Editor's Note: Some photos of the areas mentioned may be seen at these sites: http://www.embratur.gov.br/b2.htm has photos of several areas in Brazil http://www.turismo.gub.uy/artiga_s.html Artigas, Uruguay