在西南地区的一些石灰岩山城小镇里,常常可以看到砌墙的基石、建陵的碑石或铺路的条石上,有许多多边形的龟裂花纹,大家叫它“龟纹岩”。“龟纹岩”对一般民用建筑来说,真是天从人愿,因为它每隔二三十厘米厚就有一个自然层面,石工们只要一撬就开,形成上下平整的石面,再凿齐四周就很容易成型了。更为令人喜爱的是“龟裂”花纹呈褐黄色或暗红色,衬底为浅灰色或褐灰色,就像人工镶就的花纹一样。大自然赋予人们的并不以此为满足,在龟纹岩中还经常见到一种雪白晶莹的长鞭形化石,一节节似竹笋,人们叫它“竹笋石”;又因一层层像宝塔,也有人称“宝塔石”;还由于它的横断面一圈圈如太极,所以亦名“太极石”。北宋江西诗派创始人黄庭坚发现了一块竹笋石后,磨成光滑的长方形六面体,并题诗曰:“南崖新妇石, In some limestone mountain towns in the southwestern region, you can often see the cornerstone of the brick wall, the built stone monument or the paved stone. There are many polygonal crack patterns, which we call ”moire“. ”Moori rock “ For ordinary civil architecture, it really is from heaven, because it every twenty or thirty centimeters thick there is a natural level, masonry as long as a pry open to form a smooth stone surface, Then it is easy to shape it around again. Even more lovely is ”cracked “ pattern was brown or dark red, the substrate is light gray or brown, just like the artificial inlaid pattern. Nature gives people is not satisfied with this, often seen in the moire rocks of a whip-shaped crystal whip fossils, a festival like bamboo shoots, people call it ”bamboo shoots“; because of a Like a pagoda layer, it was also called ”pagoda stone “; also because of its cross-section circle, such as tai chi, so named ”tai chi“. Huang Tingjian, founder of the Northern Song Dynasty Jiangxi Poetry School found a piece of bamboo shoots, ground into a smooth rectangular hexahedron, and poem said: ”South Cliff new stone,