A variety of shale or clay slate, containing iron pyrites, the decomposition of which leads to the formation of alum, which often effloresces on the rock.
A timeless resource no serious scholar should be without. With more than 75,000 entries, if it is a word used in the Bible, you are sure to find it defined here.Wikipedia
A timeless resource no serious scholar should be without. With more than 75,000 entries, if it is a word used in the Bible, you are sure to find it defined here.Wikipedia
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