
1) Volcanic rock
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Literally, "little stones"; round to angular rock fragments measuring 1/10 inch to 2 1/2 inches in diameter, which may be ejected in either a solid or molten state.
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• (n. pl.) Volcanic ashes, consisting of small, angular, stony fragments or particles.
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http://thinkexist.com/dictionary/meaning/lapilli/

This lapilli was erupted by Pu`u Pua`i (gushing hill) from the summit of Kilauea Volcano in 1959 and fell to the ground about 800 m downwind. Credit: U.S. Geological Survey Rock fragments between 2 and 64 mm (0.08–2.5 in) in diameter that were ejected from a volcano during an explosive er...
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http://www.daviddarling.info/encyclopedia/L/lapilli.html

Literally, "little stones." Round to angular rock fragments, measuring 1/10 inch to 2 1/2 inches in diameter, which may be ejected in either a solid or molten state.
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http://www.encyclo.co.uk/local/21455

Volcanic rock materials which are formed when magma is ejected by a volcano. Typically used for mate
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http://www.encyclo.co.uk/local/22392
La·pil'li noun plural [ Latin
lapillus a little stone, dim. of
lapis stone.]
(Min.) Volcanic ashes, consisting of small, angular, stony fragments or particles.
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http://www.encyclo.co.uk/webster/L/13

A fragment of volcanic rock formed when magma is ejected into the air by expanding gases. The size of the fragments ranges from sand- to cobble-size.
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http://www.scientificpsychic.com/etc/geology-glossary.html
No exact match found.