Digging into Apatite: A Gleaming Gem of the Ottawa Valley and Beyond

Nestled in the heart of nature’s bounty, the Bancroft, Ottawa and Mont-Tremblant corridor boasts a hidden mineralogical treasure: Apatite. This vibrant mineral, gleaming in reds, greens and blues, has captivated collectors and geologists alike. But there’s more to apatite than meets the eye—it’s a story of geology, industry, and a dash of history.

Apatite’s Allure

With a modest hardness of 5 on the Mohs scale, apatite might not be the toughest gem, but its stunning colors make it a prized find. The region’s fluorapatite (the most common variety of apatite), in particular, dazzles with hues ranging from seafoam green and brownish red to deep ocean blue. While its softness and brittleness make it a rare choice for jewelry, collectors treasure its aesthetic appeal as well-formed hexagonal crystals ranging from a few mm up to 2 metres long and weighing over 200 kg have been discovered.

From Fertilizer to Collector’s Item

Apatite’s phosphate content once fueled a thriving mining industry in the area, feeding the demand for fertilizers. However, the discovery of rich guano deposits—yes, bird and bat droppings—offered a more accessible source of phosphates, leading to a decline in apatite mining. As the guano trade and other phosphate deposits boomed, apatite mining in eastern Ontario and western Quebec dwindled, leaving behind a legacy of stunning mineral specimens and small scale old mine pits and dumps ripe for exploration by mineral collectors. Today, rockhounds can still unearth these gems, a testament to the area’s rich geological history.

Apatite: A Gem of the Past and Present

Whether you’re a seasoned collector or a curious newcomer, apatite offers a vibrant glimpse into the geological wonders of the Ottawa region. Most apatites were formed between 1.3 – 1 billion years ago during the tectonic collisions and subsequent high-grade metamorphism that created the 2,000 km long Grenville geological province. These marvellous crystals occur in several different host rocks, including the enigmatic, coarse-grained “calcite vein-dikes” that contain so many great crystals of apatite, titanite, pyroxene and phlogopite mica among others at innumerable sites throughout the Grenville. Other prospective host rocks include the so-called “metamorphic pyroxenite” which consists largely of diopside with lesser intermixed apatite, and local bands and pockets in marble and calc-silicate rocks. So, grab your rock hammer, don your explorer’s hat, and dive into the sparkling world of apatite—where every discovery is a gem of a story.

A Treasure Hunt Awaits

For those eager to start their own apatite adventure, there are a number of locations to consider.  Here are three examples that are open to the public:

• Miller Property near Eganville offers a prime spot to find these colorful crystals.
• Yates Mine near Otter Lake, Quebec has awesome green to brownish red apatites, often in a salmon-colour calcite matrix.
• Titanite Hill, west of Bancroft offers many veins of calcite laden with apatite and other minerals.

Information on these and hundreds of other sites can be found on the website Mindat.org as well as a series of mineral collecting guidebooks by Ann Sabina of the Geological Survey of Canada; some of these guidebooks are now available as free downloads at https://www.mindat.org/mesg-315102.html.