| http://www.w3.org/ns/prov#value | - When weathered they are filled with calcite, chlorite, serpentine[?] and, especially where the lavas contain nepheline[?] or leucite[?], are often rich in zeolites, such as analcite, prehnite, natrolite[?], scolecite[?], chabazite[?], heulandite[?], etc.
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