Celestine, colored orange from trace quantities of copper, is found at a number of places in the Niagara Escarpment. A very unusual color for the mineral, but surprisingly abundant in specific strata at certain localities. Unlike celestine from the many other localities in Ontario, one seldom sees a solitary freestanding terminated orange crystal, they form blades and generally grow to entirely fill the vugs, yielding platy masses to 10 cm or so. Any actual crystal faces, found in rare openings, are usually white.

Celestine, Glen Williams Quarry, Halton Region, Ontario

90 mm across, image courtesy of Maggie Wilson

Celestine, Deforest Quarry, Inglewood, Peel Region, Ontario

60 mm across, image courtesy of Maggie Wilson