Hackmanite

One of the stones on my wish list from Tucson this year was Hackmanite, however the only stones I saw were translucent at best - so imagine my surprise when Pala International posted this beauty for sale!


The May Gem News from Pala International reports that:

Hackmanite is a phenomenal variety of sodalite and a member of the feldspathoid group, hackmanite is mostly found in a translucent cabochon form. This month we feature a transparent faceted hackmanite from Afghanistan. This gem is near-flawless and exhibits all the unusual optical characteristics associated with hackmanite.

Hackmanite is known for its unique color-shift phenomenon when subjected to warm white light or daylight. The phenomenon is known as tenebrescence. Hackmanite will often increase in saturation when allowed to be “charged up” in daylight and sometimes shifts between lavender and magenta hues. Long-wave ultraviolet light also brings out an amazing fluorescence, as seen directly below; in this case we see a glowing orange/yellow hue. The distinctive color phenomena are derived from the sulphur component in hackmanite’s chemistry. Light can polymerize the sulphur into different-length molecules and ions that, in turn, have different colors. (Thanks to Dr. George R. Rossman for clarification of the color phenomena science. See this Caltech webpage for more on the sodalite group.)

This stone is the May Featured Stone: Lavender hackmanite from Afghanistan, 7.87 carats, 16.28 x 11.08 x 8.64 mm. Inventory #17382. (Photo: Mia Dixon)

Bill Larson, Pala Gems to Speak at Tucson

Pala International President Bill Larson will present a free seminar at next week’s AGTA GemFair in Tucson, entitled “Collectors of Gems and Minerals: How and Why.”

The presentation is targeted at the basic-to-intermediate level:
Collector Bill Larson follows a fine tradition of a few noteworthy gem and mineral collectors such as Dr. Edward Gubelin, Dr. Peter Bancroft, and John Sinkankas whose collections have informed the industry and who were themselves inspiration for, and mentors to, Larson. In this session Larson discusses the collector’s impulse, how to build your own gem and mineral collection, and reveals some of his holdings while appreciating the import of other gem and mineral collectors.

This presentation will make a great companion piece to Jason Stephenson’s “Collecting and Investing in World Class Gemstones” featured previously in Pala’s Gem News.

Seminar: Collectors of Gems and Minerals: How and Why

When: Saturday, February 7, 2009

Time: 1:00 – 2:00 p.m.

Where: AGTA GemFair, Maricopa Room, Tucson Convention Center

See Pala International’s page on the Westward Look Show site.

Pala International will be represented in Tucson as follows:
Event: AGTA GemFair

When: February 4–9, 2009

Where: Tucson Convention Center

Booth: 1016–1018

Event: Westward Look Mineral Show

When: February 6–9, 2009

Where: Westward Look Resort

Suite: 236Website: Official show website

Event: 55th Annual Tucson Gem and Mineral Show

When: February 12–15, 2009

Where: Tucson Convention Center

Booth: Aisle 5 East

We look forward to seeing our many friends there. Visit the Pala International Show Schedule for future events.