Volume 23, Number 8, October - December 2008

Voume 23 Number 8  
  • Odontolite
  • A colourless natural diamond showing strong orange and mixed coloured fluorescence images
  • Upper Burma Ruby REgulation
  • Hackmanite, Tugtupite and Afghanite Tenebrescence
  • Spoonmaker's Diamond
  • Economy Stereo Zoom MIcroscope

(Follow this link for abstracts of past issues)

ODONTOLITE

Bobby Mann1, Brian Jackson2, Dr. Grahame Brown3 (dec.)

1Temple Hills, Maryland USA
2National Museums Scotland, Edinburgh, Scotland
3Queensland Australia

ABSTRACT
 The authors trace the history of odontolite, its gemmological relationship with turquoise, its suggested causes of colour, and its characteristic visual features by combining their protracted research and findings into one paper.
Key-words:
odontolite, turquoise, history, blue, apatite, vivianite, copper, iron, manganese, mastodon, dinotherium, tusk, tooth. ivory, bone, phosphate

A COLOURLESS NATURAL DIAMOND SHOWING STRONG ORANGE
AND MIXED COLOURED FLUORESCENCE IMAGES

Taijin Lu Ph.D., Tatsuya Odaki G.G., Kazuyoshi Yasunaga G.G. and Hajime Uesugi G.G.

ABSTRACT
 Among non-blue coloured fluorescence seen in colourless diamonds, orange fluorescence is extremely rare and weak so that the related causes remain unclear. The laA>B colourless diamond investigated displayed strong orange fluorescence under the long-wave UV lamp and mixed coloured fluorescence when examined by the DiamondView system. The UV-Visible absorption spectrum and photoluminescent emissions reveal a weak 480 nm band defect and possible Ni related information, which could be the cause for the orange fluorescence.

Key-words:
Diamond, fluorescence, ultraviolet, orange, mixed colour, nickel

THE UPPER BURMA RUBY REGULATION OF 1887

U Tin Hlaing

ABSTRACT
 This paper describes the development of the Mogok Stone Tract by the British Company, -"Burma Ruby Mines Ltd." Subsequent to the passing of the 1887 Ruby,Regulation. The source of the comments and extracts comprising this article was the British Company Report on "Ruby Mining in Burma" 1936 which was a general historical review of the progress of mining for rubies and other gems. The original compiler of these comments and of the Report was J. G. Halford-Watkins, Company Agent at Mogok, on 16th December 1936, and these selected extracts of rather inaccessible historical information have been collated into the following review by the writer who was privileged to have had access to the original report.

Key-words:
Mogok, ruby, mining, British, report, Burma, byon

HACKMANITE, TUGTUPITE AND AFGHANITE TENEBRESCENCE AND
FLUORESCENCE OF SOME SODALITE RELATED MINERALS

John Tunzi, (CEO, "Quality Gem Rough Supplies")
Grant Pearson (Dip. Gemm. GR Dip., FGAA)

ABSTRACT
 The tenebrescent behaviours of hackinanite specimens from Afghanistan and Myanmar were investigated and compared with those of two specimens of tugtupite from Greenland which is also widely reputed to display this effect. The hackmanites displayed variable tenebrescence but the tugtupite specimens were largely inactive. The fluorescent and phosphorescent behaviours of hackmanite, tugtupite and of afghanite, a chemically closely-related mineral found in the same vicinity as Afghani lapis and hackmanite, were compared. Rare specimens of facetted transparent hackmanite and also of afghanite have recently become available for investigation and for collectors of unusual gems.

Key-words:
Hackmanite, tugtupite, afghanite, tenebrescence, photochromism, fluorescence, phosphorescence, feldspathoids.		  


Tenebrescent response of Afghani hackmanite crystal on matrix before any exposure, after 30 seconds exposure to bright sunlight, after five minutes exposure to bright sunlight and then being kept in the dark for a further two days.

ACCOUNT OF THE 1968 INSPECTION AND AUTHENTICATION OF THE
KASIKCI OR SPOONMAKER'S DIAMOND

Asst. Prof. Dr Murat Hatipoglu

Dokuz Eylul University, IMYO, Izmir Multidisciplinary Vocational School, Gemmology and Jewellery Department, Dokuz Eylul Gemmological Testing Laboratory

ABSTRACT
 This paper is a sequel to the earlier paper by the author which discussed some of the stories and legends concerning the possible origins of the 86 carat Spoonmaker's Diamond, which is also called the Kasikci Diamond. it is currently exhibited in the Topkapi Palace in Istanbul, Turkey. The name refers specifically to the diamond itself as well as to the 38 grain gold jewel in which it is mounted including the 49 additional cut diamonds set around the main stone. The jewellery was earlier investigated in some detail in 1968 by officers of the Turkish Government to establish its propel-ties for provenance and security purposes, but the first account of the observations arising from this inspection are now reported in this paper.

Key-words:
Diamond, Spoonmaker's, Kasikci, inspection, Topkapi, Kumuk.		  

The Spoonmaker's Diamond
The Spoonmaker's Diamond. The name refers both to the jewellery and the main diamond of 86 carats.

ECONOMY STEREO ZOOM MICROSCOPES

A report from the GAA Instrument Evaluation Committee
Trevor Linton, Anne Paul, Roy Beattie

ABSTRACT
 Relatively few new types of gemmological microscopes have appeared on the market and even fewer improvements to existing instrument designs have occurred in the past twenty years. However, an interesting development is the use of above average quality of optic paths in newer economy versions of microscopes.