Sentence:  The small clouds which chequered the sky, as they passed along, spread their flitting shadows on the distant mountains, and seemed to <WSD>marble</WSD> them; a beauty which I do not recollect has struck any painter. 
Meaning of the word marked with <WSD> tags:  To cause (something to have) the streaked or swirled appearance of certain types of marble, for example by mixing viscous ingredients incompletely, or by applying paint or other colorants unevenly.