| Shallow pits were excavated, and several small datolite nodules were recovered that had a somewhat almond shape and a dark black chloritic rind. |
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| With the dumps gone, datolite collecting switched to the accessible underground workings of the Michigan mine. |
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| Porcelaneous datolite occurred in the amygdaloidal lodes as veins, vesicle filling, and nodules. |
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| Through the years, articles on datolite have periodically appeared in mineral magazines. |
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| The datolite from this locality also showed traces of platinum but in insufficient quantities to be the coloring agent. |
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| Both men were usually in the boat, one rowing and the other dropping a weighted float bobber on the datolite. |
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| Microscopic examination of datolite nodules from a number of localities shows that native copper is probably the most common impurity. |
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| This unique form of datolite hails from the legendary Lake Superior copper deposits, home to the world's largest occurrence of native copper. |
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| A few people still poke around what is left of the mine dumps, but a datolite nodule is rarely found. |
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| In these steep underwater cliff areas were chimneys of gravel that contained datolite nodules. |
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| Many of the early datolite nodules recovered were dark purple with a distinctive black rind. |
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| Crystallized copper could still be found in the mined-out stopes, but we didn't find any datolite. |
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| This datolite conforms to the outline of the vesicles, and the rim or rinds of the masses are semismooth and usually coated with a dark green to black chloritic mineral. |
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| When the calcite was dissolved with dilute sulfamic acid, it was noted that white semitranslucent florets of datolite occurred on the crystalline copper. |
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| Sukow suggested that the coloration may be due to aggregates of acicular crystals of copper minerals scattered or concentrated throughout the datolite nodule. |
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