China (Mainland)
The volcanic in China is a kind of basalt with about 10 percent gas holes. It is hard and gray, needn't polish. As a kind of ideal decorative material, it makes the square, the tourist attraction, or the courtyard simple and unsophisticated, serious and solemn. It also can absorb the sound and dust indoor. The site of BOAO Forum Asian and the 53rd world miss final are widely decorated by the volcanic. we aslo can make the volcanic into stone table, stone chair, stone door, stone lamp and stone mill. They are very usefulness and interesting.
The magma was brought to the surface of the earth when the volcano erupts, without the pressure; it cools quickly and form many gas holes. According as gas hole, the volcanic divided into tiny holes volcanic, small holes volcanic and big holes volcanic. The tiny gas holes,less than a millimeter, are regular, on the contrary. The smaller gas holes, about 5-15 millimeter, are irregular, and like honeycomb. The bigger gas holes are more than 15 millimeter. So it is also called honeycomb stone.