Schorl

• (n.) Black tourmaline.
Found on http://thinkexist.com/dictionary/meaning/schorl/

schorl

(from the article `greisen`) Greisen is closely connected with schorl, both in its mineralogical composition and in its mode of origin. Schorl is a pneumatolytic product ...
Found on http://www.britannica.com/eb/a-z/s/44

schorl

noun black tourmaline
Found on https://www.encyclo.co.uk/local/20974

Schorl

Schorl (shôrl) noun [ German schörl ; confer Swedish skörl .] (Min.) Black tourmaline. [ Written also shorl .]
Found on http://www.encyclo.co.uk/webster/S/31

Schorl

Schorl is a rock comprised of quartz and black tourmaline (schorl). It is of igneous origin and occurs associated with granite and crystalline schists. It has a granular texture and is usually a grey colour. It is a frequent associate of tin-bearing veins in all parts of the world.
Found on http://www.probertencyclopaedia.com/browse/HS.HTM

schorl

tourmaline
Found on http://phrontistery.info/s.html
No exact match found