DONNAYITE-(Y): NO HISTORICAL OF POLITICAL SIGNIFICANCE

 

Donnayite-Y, what a mineral! Wikipedia, that fount of all knowledge, describes (accessed February 2025) donnayite as having no historical or political significance, no common uses, no uses in fabrication of products, and most people do not even know it exists. Now, that is quite a buildup for any mineral and is one reason that I purchased the lonely perky box wallowing in a dusty tray.

The Fall of 2024’ was a busy time of year for me as after the move from Colorado Springs to Wisconsin I was valiantly trying to unpack my mineral specimens, along with numerous boxes of “household” you name it”. I was hoping that the area would offer a few rock and mineral shows that would break up my tedium of unpacking—but not much luck in that area. However, I did notice that Madison, home to both the UW Badgers and the seat of the Wisconsin government, was holding a show in late November. When the appointed weekend arrived the ole car was heading east to the Madison Gem and Mineral Club exhibits and show.

Madison Gem and Mineral Club Show 2024

I found several items with the show to be interesting, not the least of which was the $10 parking fee in addition to the gate fee plus the gasoline to and from Madison. Those expenses did not seem like a whiz bang deal for a non-Tucson show. However, rockhounds seemed to be hungry for a "show" and the event was packed on Saturday. 

I also found that the Midwest shows host a different variety of vendors than the Rocky Mountain shows. And that is understandable as the cratonic rocks of the Midwest are primarily Paleozoic and sedimentary in origin. As a result, vendors hustled “lots of” fossils, many of which were quite beautiful, tables of cab jewelry (few faceted pieces), slabs/hunks of polished limestone, plus a variety of agates, or at least chalcedony/flint nodules with lines. However, vendors selling “hard rock” minerals were very scarce, and almost non-existent. As a result, I purchased only a single specimen, that being the aforementioned donnayite-Y.

Other than the lonely perky box previously noted, donnayite-Y has, at least to me, an interesting chemical composition: three water molecules, six carbonate anions (negative charge), and four cations (positive charge)—sodium, calcium, strontium, yttrium. In fact, since yttrium is a rare earth element (REE) the Y stuck on the end of the written composition is, wait on it, an indication that yttrium is present: NaCaSr₃Y(CO₃)₆--3H₂0. It seemed to me that any mineral with yttrium ought to be worth a couple of bucks bucks. 

The previous owner of this specimen had a ed arrow pointing to this apparent stack and identifying such as donnyaite. Width FOV ~7 mm.

Donnayite-Y, is not only an “insignificant” mineral but one that seems quite difficult for a rockhound of my “quality” to identify. MinDat noted that donnayite-Y is often yellow in color but ranges to colorless, white, grey or perhaps reddish brown if included with hematite. The crystals are quite small in the .5 to 1.0 or 2.0 mm range, and soft (~ 3.0 Mohs). MinDat, and other mineral descriptive publications, seem to heavily rely on barrel-shaped, stacked layers as the major element in identification. Unfortunately, it seems that in many specimens donnayite-Y is platy or columnar or coarsely granular in appearance and then becomes even more difficult for me to identify. The material identified by the previous owner points to a apparent stack of small plates; however, I would not bet the farm that the ID is correct. Would I regret a incorrect ID? Maybe, but I have spent too many career years trying to paint everything in black and white and good and bad and right or wrong. Now I try to live a life of calm knowing that perhaps I will not succeed. Bit it gnaws on me that there is not any chance of success unless I try just one more time! As my hero Mark Twain once said, “the secret of getting ahead is getting started.” So now I am looking for a new specimen of donnayite-Y!

The specimen I purchased came from one of the quarries at Mount St. Hilaire probably the Poudrette quarry located in the East Hill suite of the Mont Saint-Hilaire alkaline complex (igneous rocks containing a high concentration of sodium and potassium, more so than in other igneous rocks and therefore containing feldspathoid minerals [lots of nepheline]) is one of the world’s most prolific mineral localities, with a species list exceeding 365 (MinDat now shows 433 valid minerals). No other locality in Canada, and very few in the world have produced as many species. With a current total of 50 type minerals (MinDat now lists 71 Type Minerals), the quarry has also produced more new species than any other locality in Canada, and accounts for about 25 per cent of all new species discovered in Canada.

Above is taken directly from the following:

GEOLOGICAL ASSOCIATION OF CANADA, MINERALOGICAL ASSOCIATION OF CANADA, 2006 JOINT ANNUAL MEETING MONTRÉAL, QUÉBEC

FIELD TRIP 4A: GUIDEBOOK, MINERALOGY AND GEOLOGY OF THE POUDRETTE QUARRY, MONT SAINT-HILAIRE, QUÉBEC

Charles Normand & Peter Tarassoff

Microsoft Word - GuidebookMSHfinal2-JP2.doc (mcgill.ca)