Tufa

Cellular rock; porous limestone.
Found on http://www.encyclo.co.uk/local/20018

tufa

[n] - a soft porous rock consisting of calcium carbonate deposited from springs rich in lime
Found on http://www.webdictionary.co.uk/definition.php?query=tufa

Tufa

a very light sponge-like limestone formed in aireated springs, and used decoratively eg in grottos or where lightness is important eg at the top of domes. - see Stone/stonework
Found on http://www.encyclo.co.uk/local/20935

Tufa

A porous, grey stone of volcanic origin.
Found on http://www.crsbi.ac.uk/resources/glossary.html

tufa

<chemical> A soft or porous stone formed by depositions from water, usually calcareous; called also calcareous tufa. ... A friable volcanic rock or conglomerate, formed of consolidated cinders, or scoria. ... Origin: It. Fufo soft, sandy stone, L. Tofus, tophus. Cf. Tofus, Toph, and Tophin. ... Source: Websters Dictionary ... (01 Mar 1998) ..
Found on http://www.mondofacto.com/facts/dictionary?tufa

tufa

calc-tufa noun a soft porous rock consisting of calcium carbonate deposited from springs rich in lime
Found on http://wordnetweb.princeton.edu/perl/webwn?s=tufa

Tufa

• A friable volcanic rock or conglomerate, formed of consolidated cinders, or scoria. • A soft or porous stone formed by depositions from water, usually calcareous; -- called also calcareous tufa.
Found on http://thinkexist.com/dictionary/meaning/tufa/

TUFA

Spongy or vesicular calcium carbonate deposited from spring, river or lake waters. Cf. travertine.
Found on http://www.cancaver.ca/docs/glossary.htm

tufa

tufa: see travertine.
Found on http://www.infoplease.com/ce6/sci/A0919803.html

Tufa

Tufa (tuff or toph) is a soft white porous rock of calcium carbonate deposited from solution in spring water or percolating ground water. When compact it is called Travertine. Much of it is exceedingly light, and resembles petrified sponge. Tufa is extremely durable, and was extensively used by the Romans for the external facing of buildings, as at
Found on http://www.probertencyclopaedia.com/browse/HT.HTM

tufa

Soft, porous, limestone rock, white in colour, deposited from solution from carbonate-saturated ground water around hot springs and in caves. Undersea tufa columns, such as those in the Ikka Fjord in southwestern Greenland, that form over alkaline springs, can reach 20 m/65 ft in height and grow at about 50 cm/20 in per year. They provi...
Found on http://www.talktalk.co.uk/reference/encyclopaedia/hutchinson/m0015317.html

Tufa

Cellular rock; porous limestone.
Found on http://www.castlesontheweb.com/glossary.html

Tufa

Calcareous deposit from saturated limy waters.
Found on http://www.selectstone.com/architectural-resources/stone-glossary/

tufa

the calcareous (chalky, containing calcium carbonate) and siliceous (flinty, containing silica) deposits of springs, lakes, or ground water; also a rock composed of compacted volcanic ash: in architectural terms, tufa refers to a rough facing stone applied to buildings to give a rustic look.
Found on http://faculty.bsc.edu/jtatter/glossary.html

tufa

Synonym of sinter: Mineral deposit formed by mineral-rich spring water which comes to the surface and loses its capacity to withhold the dissolved mineral, thereby depositing it and forming a growing mound. Sometimes misconceived as tuff.
Found on http://www.inlandlapidary.com/user_area/glossaryT.asp

tufa

see travertine .
Found on http://www.ge-at.iastate.edu/glossary-of-geologic-terms/

Tufa

A fine grained, porous limestone formed by chemical precipitation, often around springs.
Found on http://www.bgs.ac.uk/discoveringGeology/glossary.html

Tufa

The calcareous (chalking, containing calcium carbonate) and siliceous (flinty, containing silica) deposits of springs, lakes or ground water; also a rock composed of compacted volcanic ash.
Found on http://www.pcmg-texas.org/glossary_gardening_landscaping.htm

tufa

rock made of fine volcanic detritus
Found on http://phrontistery.info/t.html
No exact match found