Eighteenth Annual Sinkankas Symposium – Alexandrite and Other Color-Change Gemstones

• 

  Eighteenth Annual Sinkankas Symposium
      Alexandrite and Other Color-Change Gemstones

  April 25 through June 13, 2022

  (pre-recorded sessions on-demand)

  co-sponsored by
  the Gemological Institute of America, the Geo-Literary Society
  and the Gemological Society of San Diego

  Rough and cut alexandrite. Photo by Robert Weldon. © GIA.
  

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  Sinkankas Symposium – 2022

  Evan Caplan
  William Larson
  Dr. Çiğdem Lüle
  Dr. Sally Eaton-Magaña
  Niveet Nagpal
  Nathan Renfro
  Stuart Robertson
  Dr. Aaron Palke and Dr. George Rossman
  Wim Vertriest
  Robert Weldon

  A pair of faceted alexandrites: at left photographed in daylight-equivalent lighting, at right photographed in incandescent light. Photo by Robert Weldon. © GIA.

• 

  The Sinkankas Symposium

  "The best gem mineral symposium in North America."

  — John Koivula
  Analytical Microscopist
  GIA (Gemological Institute of America)

  Numerous gas bubbles within a pulled synthetic alexandrite. FOV 6.55 mm.
  Photomicrograph: Nathan Renfro.

EIGHTEENTH ANNUAL SINKANKAS SYMPOSIUM
ALEXANDRITE and OTHER COLOR-CHANGE GEMSTONES

Stuart Overlin, editor
Photographs by Mia Dixon, Orasa Weldon and Robert Weldon

Specifications: 8.25" x 10.75", digital press, soft cover, perfect binding, 110 pages, full color throughout

Publication Date: June 23, 2022

ISBN: 978-0-9915320-6-3

Table of Contents

Dedication and Acknowledgments   i

Contents   1

Speaker and Author Biographies   2

Evan Caplan   6
Alexandrite, Pricing Factors, and the Future Market

William Larson   10
Collecting Color-Change Minerals and Gemstones from World Localities

Çiğdem Lüle   14
Diaspore from Turkey

Sally Eaton-Magaña   18
Color-Change Phenomena in Diamond

Niveet Nagpal   28
Designing with Color-Change Gemstones

Aaron Palke and George R. Rossman    32
Causes of Color in Color-Change Gemstones

Nathan Renfro   40
The Microworld of Alexandrite and Other Color-Change Gems

Stuart Robertson   42
Price Trends of Alexandrite and Other Color-Change Gemstones

Wim Vertriest   48
Overview of the Geology and Mining of Alexandrite

Robert Weldon   52
Gem Photography's Biggest Challenge: Color-Change Gemstones

Ziyin Sun, Aaron C. Palke, Jonathan Muyal, Dino DeGhionno, and Shane F. McClure   60
Geographic Origin Determination of Alexandrite (from the Winter 2019 Gems & Gemology)

Karl Schmetzer   76
Pleochroism and Color Change in Faceted Alexandrite: Influence of Cut and Sample Orientation
(from the Spring 2019 Gems & Gemology)

James E. Shigley and Sheryl Elen   88
Bibliography

 

ABOUT THE EIGHTEENTH ANNUAL SINKANKAS SYMPOSIUM
– Alexandrite and Other Color-Change Gemstones (VIRTUAL)

Named for one of the most distinguished and influential figures in gemology and mineralogy, the Sinkankas Symposium is an annual event featuring presentations by noted specialists working in diverse gem-related disciplines.

The theme of the Eighteenth Annual Sinkankas Symposium is Alexandrite and Other Color-Change Gemstones. The virtual format of the 2022 symposium featured a menu of 10 pre-recorded 30-minute exclusive presentations available to view on-demand from Monday, April 25, 2022 until Monday, June 13, 2022.

The Sinkankas Symposium has been described as the most important gemological conference in North America by respected authorities on gemstones. Organized by Roger Merk for 13 years (2003–2015), this year's event is co-sponsored by the Gemological Institute of America (GIA), the Geo-Literary Society and the Gemological Society of San Diego. Bill Larson has been a generous supporter and speaker at the event since its inception.

 

EIGHTEENTH ANNUAL SINKANKAS SYMPOSIUM
– FORMAT, REGISTRATION & TIMELINE

Ten 30-minute pre-recorded presentations available for browsing on demand
at the Sinkankas Symposium EventBrite web page (now closed).

REGISTRATION: Closed.

SYMPOSIUM VOLUME: A free PDF version of the Symposium volume will be made available on June 30, 2022. (Check back here for the URL on June 30th). Pre-ordering of printed volumes (2014–2022) ended June 13, 2022. (June 2022 is the only printing scheduled for 2022.)

EVENT TIMELINE:

• Registration for the Eighteenth Annual Sinkankas Symposium (Virtual) open March 14 through June 5, 5PM PDT (GMT-7).
• April 5, 2022, 5 PM PDT – Printed Symposium Volumes may be pre-ordered at: sinkankas.dpidirect.com; back issues for past symposia – Eleventh through Seventeenth – may also be pre-ordered for a limited time.
• April 25, 2022, 9AM PDT – Start of the Eighteenth Annual Sinkankas Symposium (Virtual). Pre-recorded presentations are available to registrants for viewing on demand.
• April 25 – May 13, 2022 – Submit questions for the Speakers to: events@gia.edu. Be sure to include in the subject line: Question for [speaker name or moderator].
• May 26, 2022 – Q&A video, hosted by Robert Weldon: A compendium of speaker responses to selected attendee questions submitted through May 13th.
• June 5, 2022, 5PM PDT – Last day to register to view on-demand speaker presentations.
• June 13, 2022, 3PM PDT – (Deadline extended from June 6.) Close of the Eighteenth Annual Sinkankas Symposium.
• June 13, 2022, noon PDT – (Deadline extended from June 6.) Last day to pre-order printed symposia volumes in 2022, available at sinkankas.dpidirect.com.
• June 30, 2022, 5PM PDT – (Deadline extended from June 23.) A free PDF of the Eighteenth Annual Sinkankas Symposium volume will be available for download. Check back here for the destination URL where the PDF may be downloaded. Copyright permissions apply, no reproduction or cross-posting online, in whole or in part, is permitted, except by explicit written permission of the authors/contributors.
• July 7, 2022 – (Ship-by date extended from July 1.) Orders for printed symposia volumes ship. Please allow up to 21 days for delivery, depending upon destination. Questions about your order? Contact the print house directly at SinkankasSupport@dpidirect.com