ABOUT THE ALLARD COLLECTION
Searching the Database:
The Allard collection can be searched by district, individual mine, mineral deposit type, rock type, or mineralogy. You only need to fill out one search criteria field in order to search, which will give you the maximum number of matches. For instance, selecting “chalcopyrite” under mineralogy will show you all samples in the collection that contain chalcopyrite – lots of samples. If you want to see samples from the Chibougamau district or from the Kidd Creek mine, then select one of those criteria and you will see just those samples.
Districts and Mines:
You will note when examining the district list that not all of the entries are in fact true mineral districts. This reflects the fact that not all mineral deposits occur within a discrete geographical area containing multiple mines, and as such no district actually exists. In other instances, multiple mines of the same type occur in a discrete area, but no district name has been used and accepted, such that again, no district name exists. As such, we use recognized district names when we can, otherwise we try to use either a state or country name that is unambiguous. And for things like our suites of samples from the Bushveld and Muskox intrusions, we use "Bushveld" and "Muskox" because it simply makes sense and is unambiguous. In instances where a mine has multiple names, we try to use the most well-known name. We have come to defer to mindat.org for district and mine names whenever possible.
Economic geology is a model-driven discipline. The use of ore deposit models helps us by providing a taxonomic framework so that we can classify mineral systems on the basis of their mineralogy, structural setting, age, etc. However, we all know of mineral deposits that defy easy classification, either because they represent a new undescribed type, or because they have physical attributes that cross model boundaries between different deposit types. We’ve been working on this database for 25 years now – how we classified a particular deposit in 1998 compared to how we might classify it now reveals that sometimes things change as we learn more. A good example would be the gold deposits of the Carolina Slate Belt – they have been referred to as magmatic, orogenic, metamorphosed hot spring, metamorphosed epithermal, and metamorphosed exhalative deposits over the years. And how many of us have been in a porphyry system that magically grades, almost imperceptibly, into a skarn, like the Gaspe deposit? Our choice of deposit type for any given deposit is generally easy, but understand that sometimes ambiguity creeps in and we simply do our best. The good news is that if you call Sudbury “impact-related” and we prefer to call it “magmatic”, the samples that we’ve curated don’t care, they are there either way.
Gilles and I initially thought that we’d at most have perhaps 50 rock names, and early on we tried hard to not use a new rock name for every sample. We now have used over 600 rock names, as we’ve discovered that although that can at times be confusing, it’s better this way than being forced to call a given rock something that misses the mark in terms of accurately describing the sample. So we have “silicified volcanic” and “silicified rhyolite”, and although they are similar, you can see that they are not identical. As with ore deposit type, regardless of what we call a particular sample, the sample itself isn’t affected.
There are also certain things buried in the rock name bin - the Crowe reference collection and the Bob Carpenter polished plug collection for instance. Also in the rock name bin is a category called "regional sample" - sometimes we have samples that aren't from a specific mine, but rather from the area around the mine. These samples have high intrinsic value as they provide context for the geological environment within which specific mines exist. So if you search on the Noranda or Chibougamau district, you will see lots of regional samples, in addition to samples from specific mines within the district.
Mineralogy has been the most challenging aspect of this curation work. Gilles and Doug have done the bulk of the classification of mineralogy by looking at the samples with their naked eyes and their hand lenses. As such, they’ve perhaps made some errors. Their mantra has always been to try to err by not over-interpreting any given sample, such that if one of us thinks there might be enargite or carrollite in a sample, but we’re not sure, we don’t list it. If we do list a mineral phase, we’ve generally seen something that makes us reasonably confident in that assessment. The bottom line is that if we list a mineral as present, it is likely there. If we don’t list a mineral as present, it absolutely doesn’t mean it’s not there, it just means we couldn’t be confident enough to list it. As much as possible, we are working through the entire collection and wherever possible, using either EM or XRD to clear up ambiguities.
We’ve organized and uploaded all of our guidebook materials. When you click on an individual sample, you will see any available reference materials, with ACL (Allard Collection Library) numbers. Many are now out of print or hard to find, and contain a wealth of information about specific samples as well as maps and other reference materials. Where possible, individual samples contain field notes keying samples to specific guidebook sections and/or locations. Whenever possible, we’ll allow these volumes to circulate or make copies of select portions. References without the ACL designation are University of Georgia Department of Geology theses and dissertions that are available via the UGA Library system and in some cases, via the UGA Department of Geology.
In the fall of 2018 we began photographing each individual sample. As of spring 2023, we are roughly 90% of the way there, and most days interns are working in our collections rooms adding more pictures. We hope to continue this effort until all samples in the collection have been photographed and the images posted. Clicking on a photo on an individual sample page will open a new window with a high resolution image of that sample, and you can zoom on those images and get great close up views of samples.
What’s in the collection?:
The collection contains hundreds of suites of samples from individual mineral deposits, collected mainly by Drs. Allard and Crowe. Samples suites from specific deposits have also been generously donated by alums. Also in the collection is the polished section collection of Bob Carpenter, which includes over 500 beautifully polished plugs from a diversity of deposits, which can be searched by selecting “polished plugs” in the rock name search box. The collection also includes the Crowe reference mineral collection, which has >1000 verified reference mineral samples typically found in ore forming environments, which can be viewed by selecting “Crowe reference collection” in the rock name search box. Samples in this collection have all be analyzed via electron microprobe or XRD by Dr. Crowe to verify composition, which in most cases suffices – these patterns can be viewed by clicking on the EDS or XRD pattern at the bottom of each individual sample page. We still have certain samples that will require further work as certain minerals are either isochemical or isostructural with other phases such that we'll need to determine both composition and structure to explicitly identify these minerals.
Can I donate to the collection?:
Absolutely. Samples suites from individual deposits, or from several deposits within a district will be put in the collection, and attribution will be given to the donor. Individual samples are also welcome. We prefer to have more information for each sample than less, in particular location information within a specific deposit, which makes samples more valuable from a reference standpoint. Contact Doug at email@example.com if you have any questions.