Polished and sliced datolite nodules can show off very attractive colors. Datolite is a popular collector’s mineral, but faceted and cabbed datolites are rare.
Datolite
Value
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You’re more likely to find datolites in mineral collections than jewelry collections. However, if worn occasionally or in protective settings, these gems can make interesting conversation pieces. They can match popular opals in hardness but without the additional wear and care restrictions.
Most faceted datolite gems show pale yellowish or green colors. Some are colorless. While faceted gems have high brilliance, they have little fire or dispersion.
Massive brown or white material may yield cabochons.
Copper inclusions in material from Michigan can create striking colors.
Datolite nodules may resemble howlite. Nevertheless, their physical properties differ considerably, notably their hardness (5.5 versus 3.5 or less) and specific gravity.
Brown or white massive material will cut cabochons up to several ounces. However, gem collections seldom hold these cabochons, as it seems most collectors prefer sliced nodules. These can measure up to about 6 inches in diameter.
The best faceting material comes from Massachusetts, with fine pale green material from New Jersey. The largest gems cut from these materials range up to 5 carats.
National Museums of Canada (Ottawa, Ontario): 0.45 (colorless, Canada).
Datolite Care
Store datolites separately from other harder, well-known jewelry stones to avoid contact scratches. Clean datolites with a soft brush, mild detergent, and warm water. See our gemstone jewelry care guide for more recommendations.