I find Wikipedia a great data base giving information which no other encyclopedia would give.
I do my bit when somebody tries to mutilate (not edit) an article by, for instance, deleting whole paragraphs or links just because he/she does not like it.
Celestine is a mineral consisting of strontium sulfate (SrSO4). It is named for its occasional delicate blue color. Celestine and the carbonate mineral strontianite are the principal sources of the element strontium, commonly used in fireworks and in various metal alloys. The mineral occurs as crystals, and also in compact massive, and fibrous forms. It is found worldwide, mostly found in sedimentary rocks, usually in small quantities. Pale blue crystal specimens, as shown in this photograph, are found in Madagascar.Photograph credit: Ivar Leidus
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