basalt column 1.straight shape 2.inner side is black 3.outside is brown 4.suitable be polished finish basalt columnBS3 diameter 15cm-25cm, length 20-110cm , good texture , inner side is black, straight shape , outside is brown , suitable be polished finish . Always used as fountain, flower pot , paving stoneB5 diameter 35cm-60cm, Length 100-800cm , good texture , good to be polished ,straight ...