CALCITE (var. Abitibi Concretions)
HISTORY, NAME, LOCALITIES: Calcite-based concretions are found worldwide in sedimentary deposits, notably those of shale. The name “Abitibi” stems from the Abitibi region of western Quebec, Canada, where large numbers of distinctly shaped, calcite-based concretions occur. Abitibi-type calcite concretions also are found in the United States (northern Michigan and western Colorado).
MINERALOGY, PROPERTIES, OCCURRENCE: Calcite [calcium carbonate, CaCO3], pronounced CHAL-site, is the most abundant carbonate mineral. Calcite-based Abitibi concretions are post-depositional structures that occur in sedimentary formations, usually of sandstone, siltstone, or shale. They form when calcium-rich groundwater percolates through sediments to precipitate calcite around such nuclei as rock fragments, fossils, or bits of organic matter. The calcite acts as a cementing agent that creates the concretions in a limitless variety of shapes. Abitibi-type concretions are usually of Pleistocene age and are about 11,000 years old. Most form in lake-bed sediments. They are recovered as they weather free from eroded sedimentary formations.
METAPHYSICAL PROPERTIES, LORE, USES: According to metaphysical practitioners, calcite enhances learning abilities, reduces fear and stress, removes negative energies, and promotes creativity and imagination. Calcite-based Abitibi concretions were originally considered mysterious and once thought to be fossils or man-made. They are also known as “fairy stones” for their shapes that resemble animals and other objects. Abitibi concretions are used as display pieces and decorative items.
COLLECTORS’ INFORMATION: Abitibi-type calcite concretions are widely sought by collectors for their remarkable variety of fanciful shapes and sizes.