In the Galilee, archaeologists have uncovered a two-millennia-old quarry and workshop used for producing vessels out of chalkstone. Jews’ penchant for stone items at the time might have stemmed from the concerns of kashrut, writes Robin Ngo:
While vessels—from tableware to cooking pots to storage jars—were usually made of clay in antiquity, Jews throughout Judea and Galilee in the 1st century CE used vessels made of stone.
Archaeologist Yitzḥak Magen explains that “[s]tone vessels, unlike ceramic and glass vessels, were not subject to impurity.” . . . It made sense to purchase a vessel that could not become unclean, for once a vessel became ritually unclean, it had to be taken out of use. An impure pottery vessel, for example, had to be broken.
Read more on Bible History Daily: http://www.biblicalarchaeology.org/daily/ancient-cultures/daily-life-and-practice/jewish-purification-stone-vessel-workshop-galilee/