Scottish Gemmological Association

Presentations

Friday, 28th April, 2017

6.00 to 7.00p.m

Registration and a welcoming drink to be enjoyed with friends old and new

7.00 - 8.00p.m

David Callaghan on Andrew Grima

This talk illustrates the career of probably the UK’s foremost jewellery designer of all time. Andrew Grima joined the trade just after WWII and soon established himself with his unique and highly personal designs. For over 50 years his work flourished and is now highly sought after world-wide.

Andrew Grima,  2.97-carat fancy greyish-blue diamond surrounded by sapphires and white diamonds sold for £1.5 million in 2015 (Bonhams)

Andrew Grima,  2.97-carat fancy greyish-blue diamond surrounded by sapphires and white diamonds sold for £1.5 million in 2015 (Bonhams)

from 8.00p.m    Buffet Dinner

 

Saturday, 29th April, 2017

Morning from 9.00a.m,

09.00 - 09.15a.mWelcome

09.15 - 10.15a.m    Ken Scarrett:  Pearls, Natural P. radiata Pearls from Bahrain and Natural P. maxima pearls from Australian waters followed by a description of Experiments in Producing Atypical Bead Cultured Pearls in P. maxima.

Details of the history as well as modern day pearling in the waters of Bahrain are presented along with an overview of the indigenous industry.  Also covered will be details of the retrieval of natural pearls from P. maxima in Australian watersas well as the examination results of some of the pearls.

In addition, since approximately 2010 a practice has been developed of using low quality natural pearls as the substrates for cultured nacre growth. In order to gain a better understanding of the processes used and the results likely to be obtained from the use of unconventional culturing techniques, experiments were conducted,  details of which will be presented along with the results and RTX and µCT images of some of the successful operations.

10.15 - 10.45a.m   Coffee

10.45 - 11.15a.m   John Harris:  Photospectroscopy,  Improving your Image

Although the direct vision spectroscope is of considerable help in gemstone identification it is still regarded by many as difficult to use and of little diagnostic value compared to the photo-spectrometer. To interpret their results one must first acquire a good image, this is essential if they have to be recorded for future reference.

John shall therefore try to bridge the gap between these two instruments and explain how to photograph the image through the spectroscope or process and edit the plot displayed in the spectrometer. This may help to illustrate the correlation between the two images which both interpret the gemstone’s reaction to light by their own particular method.

11.15 - 12.15p.m   David Fisher:  

Synthetic Diamonds: Recent Developments and Improvements in Detection

The last few years have seen significant developments in the growth of synthetic diamonds using both the High Pressure High Temperature (HPHT) and Chemical Vapour Deposition (CVD) synthesis routes.

The potential technical applications of synthetic diamond have driven much of this development, but this talk will highlight changes that have implications for the gem diamond market and the improved detection methods that are now employed by gemmologists to continue to support consumer confidence.

Enhancements in the capabilities of the De Beers verification instruments and the latest instrument to screen large volumes of melee sized stones will also be presented.

red diamonds with text.jpg

 

Break for Lunch, 12.15 - 2.15p.m

 

2.15 - 3.00p.m  Alan Hodgkinson: A Zircon Insight

A look at the  consequences to breakdown of the zircon's partial to total disintegration of its original tetragonal crystal system. This is due to the effects of local radiation from the Sri-Lankan rocks and the interesting gem products which resulted in the three zircon types: 'High', Intermediate, and 'Low'. The presentation will also include the efforts to reverse the effects of radiation damage, and the wide  gemmological spread of zircon properties which can for the most part be seen with our standard gemmological tools, plus a little help from 'Visual Optics'. 

3.00 - 3.30   Stuart Robertson: Adrift in the Market

Colored stones' quest to gain market share in a diamond dominated trade. This PowerPoint presentation will discuss current issues in the colored stone industry and their influence on supply, demand and price. The discussion will include the rise of large scale mining in the colored stone trade, the elusive standards of lab reports and the unintended consequences of ethical sourcing.

3.30 - 4.00   Break for Coffee

4.00 - 5.00  Vincent Pardieu:  New blue sapphire discovery in Madagascar

New discoveries of fine quality blue sapphire sizes suitable for large fashioned gems are always welcomed by the gem trade. In the last decade and half, the island of Madagascar has emerged as a globally important source of gem quality corundum.

However, the latest find of attractive large stones at Bemainty is problematic for the trade. Although it has produced more fine blue and padparadscha type sapphires than any other recent Malagasy deposit in just a few months, it is located deep inside a designated conservation area where mining is prohibited by the government and the arrival of thousands of people determined to mine challenges conservation efforts

 

Evening from 7.00 for 7.30p.m,

Drinks Reception followed by Gala Dinner
 

Sunday, 30th April, 2017

Morning, from 9.00a.m

09.00- 10.00   Ken Scarrett:  Interesting Challenges in the Identification of Rubies

This presentation discusses the complexities and difficulties that have evolved for gemmologists when traders and some laboratories prioritise commerce or emotion over facts and plain language.

The association of ruby with treatments that result in an addition of glass to the final product began in 1984 with the appearance on the market of Thai origin rubies in which cavities had been filled with glass, a treatment that had evolved into glass crack filling by 1987.  Ken will discuss this and the ongoing problems and developments of this practice and how the trade has handled them.

Ken will also discuss the examination of heated rubies and how this form of treatment may be identified,  referencing a recent concern with Mozambique rubies being heat treated in Sri Lanka. 

Also he will touch on the subject of man made rubies, specifically some received in laboratories in 2012 with unusual inclusions which provided a challenge in terms of determining their natural or synthetic origin.

10.00 - 10.15   Gem-A update

10.15 - 10.45   Coffee

Coral and turquoise needlepoint squash blossom necklace by Zuni jeweller Smokey Gchachu (b.1956), made 2015

Coral and turquoise needlepoint squash blossom necklace by Zuni jeweller Smokey Gchachu (b.1956), made 2015

10.45 - 11.45   Henrietta Lidchi:  A Tradition of Innovation: Native American Jewellery in focus.

Southwestern jewellery in its union of blue stone and white metal is an iconic art with a compelling history, encapsulating the persistence of tradition and the vitality of Native American communities and their contemporary artistic practice. Drawing from museum collections in the UK and the USA, this lecture will consider the punctuated history of Southwestern jewellery looking at key historical junctures when controversies or events caused the representation and interpretation of Southwestern jewellery to expand and shift, from ornament to craft to curio to art.

11.45 - 12.15   Awards:  Gemmology students and GemSet Competition winners

After the morning's presentations, we will be making awards to Gemmology students and to out Student GemSet Competition winners.  The prize winning pieces will be available to view at this time and will be featured on our website.

Afternoon, from 1.15p.m

 

Evening, departing hotel at 7.00p.m

Dinner at The River House, Stirling

 

Monday 1st May, 2017

10a.m

Depart Hotel to Stirling for Castle and City walking tour.

 

PLEASE NOTE:  This is the expected running order, however the timings may need to be adjusted slightly.

Further detail of the talks and speakers will follow shortly on the relevant pages