Minerals are a bit like trading cards: if you have duplicates that your friends don’t have, and vice versa, a bit of school-yard trading occurs. All museums with mineral collections have within them what is known as an exchange collection. This collection is often material that has been collected by that museum’s staff during field work and collecting trips and is often local, or it is samples from localities that were part of a research programme.
The sole purpose of this exchange collection is for trading with other museums and mineral dealers, and as research material for other scientists. Quite often, it contains species from localities that, although common to one museum’s region, are considered rare and unique to a museum on the other side of the world.
The Canadian Museum of Nature’s exchange collection contains many rare species from Mont Saint-Hilaire, Quebec, localities within the Outaouais region such as road cuts along the new sections of Highway 5, as well as mineral samples from field trips to Rapid Creek, Yukon; Baffin Island, Nunavut; Greenland and Norway.
During a recent trip in Australia to further some research projects, I had the opportunity to visit colleagues and friends at the Museum Victoria in Melbourne.
Being from opposite sides of the planet, we see each other at conferences every couple of years and keep contact through email, but face-to-face visits are always better, especially when it includes tours of their new geology, mineralogy and palaeontology galleries (Dynamic Earth and 600 Million Years: Victoria Evolves), as well as a behind-the-scenes look at their natural-history-collections holdings and research labs.
While visiting, I had the opportunity to search through their exchange collection in order to choose mineral samples to bring back to Ottawa. This collection of Australian “trading cards” is dominated by minerals from localities within the state of Victoria, many of which have been collected and studied by Museum Victoria mineralogists Bill Birch, Dermot Henry and Stuart Mills.
It was an opportunity to acquire rare species or species from specific Australian localities that are not represented in the Canadian Museum of Nature’s collection. Facing a wall of open mineral cabinets full of rare and beautiful specimens and being told “take what you want” elicits the same response you would get if you took a child into a candy store and said the same thing: “Woo hoo!!!”
After a number of days of visiting, working on data collected in Sydney the week before, and browsing through the many drawers of Australian minerals, I chose a suite of samples that did not have equivalents in our own collection—samples of copper-bismuth phosphate/vanadate minerals from Morass Creek, Benambra (Victoria), rare-earth element-copper minerals from the Paratoo copper mine, Yunta, Olary Province (South Australia), beautiful andradite garnets from the Kara Mine (Tasmania), and a fabulous saleeite sample (a magnesium-uranium phosphate mineral) from Jabiru (Northern Territory). After carefully packing the minerals in what I was told was “archival-quality dunny paper”, the samples were boxed up and brought back to Ottawa as part of my carry-on.
Exchange collections are an important part of any museum mineral collection. Trading samples with other museums allows us to acquire specimens that we would otherwise not be able to purchase or collect, adding to the species and locality diversity in our own collection. These samples can then be used for a multitude of purposes: display, education or research.
Back here at our research and collections facility, the Australian samples are being prepared and catalogued for inclusion in our own collection. Each sample is being visually examined and described before being “finger printed”—powder X-ray diffraction patterns are being collected for the individual minerals on each sample for future reference. Once each sample has been described, analyzed and assigned a catalogue number, it will become a permanent part of the national mineral collection here at the museum.
In return, as you read this, a box of carefully packed mineral samples from our exchange collection is flying across the Pacific Ocean to the Museum Victoria, where they will become part of their permanent collection. As with trading cards, everyone comes out of a trading session happy, holding cards they didn’t have to begin with.