en2015-08-18 18:07 PM CESThttp://inspire.ec.europa.eu/codelist/CommodityCodeValue/spongolite:1http://inspire.ec.europa.eu/codelist/CommodityCodeValue/spongoliteSpongolite is a stone made almost entirely from fossilised sponges. It is light and porous. - http://en.wikipedia.org/wiki/Spongolite