Gemstone storys
minereports and manuals for gemmological tools

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        Gemstone storys   by Hubert Heldner
Perfect faceting angles versus excess weight
Colorchange in Hackmanite a variety of Sodalite
Incredible gemstone stories
The heattreatment of a beryl to change its color
The history of gemstone carving
Stabilisation of gemstones
Trade names of gemstones.     Not translated see D / F
Comparison between perfect and wrong facet angles -
for a barion and a ceylon cut
for two otherwise identical brillant cuts
Before and after recutting for best brilliance.

        Manuals for gemmological tools   by Hubert Heldner
The chelsea, emerald, jadeite filter
The loupe
The diamond moissonit tester
The hydrostatic balance
The refractometer
The dicroscope
The polariscope
The conoscope
The use the poket lamp for rough stone grading
The spectroscope
The spectral lines
The digital refractometer - Test report

        Jewellery photography   by Hubert Heldner
Photograpy of jewels and gemstones with the clouddome

        Jewellery projects   by Hubert Heldner
How to measure a ring size accurately
Butterfly pendent a step by step instruction.
Entourage ring a step by step instruction.
Flower broach a step by step instruction.
Skapolith necklace a step by step instruction.
The granulation an egyptian and etruscan soldering technique.

        Gemstone cutting projects   by Hubert Heldner
Sunstone carving a step by step instruction.
Chrysopras flower carving a step by step instruction.

        Mine reports   by Hubert Heldner
Tanzania Gemstone Safari Newsletter September 2017
Tanzania Gemstone Safari Newsletter September 2016
Tanzania Gemstone Safari Newsletter September 2015
Tanzania Gemstone Safari Newsletter April 2014
Tanzania Gemstone Safari Newsletter Mai 2013
Tanzania Gemstone Safari Newsletter October 2012
Umba Vally sapphire mine dig in Tanzania 2008
Umba Vally sapphire mine dig in Tanzania 2007
Umba Vally sapphire test dig in Tanzania 2007
Idar-Oberstein the city of gemstone carvers 2006
A Gemstone Safari in Tanzania.
Juniperridge Opal mine in Oregon, visit in 2005
Dustdevil Sunstone mine in Oregon, visit in 2005
Mining techniques. A visit to the silver mines "St. Louis" and "le chêne" in St. Marie aux Mines 2004
Juniperridge Opal mine in Oregon 2003
Dustdevil Sunstone mine in Oregon 2003
Gemshow in Tucson 2003.

        Important publications related to gemstones
Shape of things to come Designers conjure images of the future of jewelry by Darren Arnold.
Europe Correspondent of www.colored-stone.com AGTA Gemstone enhancment chart
A brief review of gemstone optical properties
from a lapidary's perspective by Sandrine Kunz CHF 15.-
The fine Art of Gemstone Carving by Katerina Kestemont CHF 6.-

 
Pendant realised by Hubert Heldner 
Turquoise cut by Katerina Kestemont



Hubert Heldner