What rock does the bluestone in Longchang belong to?

1. bluestone. Can be used as building materials, tablets, etc. Can be used as building materials, tablets, etc. Han Dong Fang Shuo's The Miracle of Nakano: "There are palaces in the east, bluestones as walls ... and silver plaques and bluestone carvings at the door." Tang Bai Juyi's poem "Bluestone": "Bluestone comes from Lantian Mountain and is transported to Chang 'an by car. The 14th time of Water Margin: "The monk pointed to a place and taught me to cut a pagoda with bluestone and put it there to hold the stream. "

2. refers to the color and quality like bluestone. Song Mei Yao Chen's poem "Fishing for Crabs": "Old crabs are weather-beaten, with purple claws and bluestone shells."

3. The common name of limestone.

Bluestone is mainly composed of (Zhangxia Formation E2) light gray thick-bedded herringbone and thick-bedded herringbone with leopard limestone. The surface is gray, and the fresh surface is dark gray fish-like structure, block structure and strip structure. It consists of two parts: fish pattern and glue structure. Fish grains account for about 60%, with a particle size of 0.5 mm, and the fish grains are radial and concentric ring structures. Most of them are normal catfish and mutant catfish, and some are deformed catfish, which are bonded into fine particles and a small amount of clay. Leopard limestone: light gray-grayish yellow, fresh surface brownish yellow and gray, local brownish red, gray matrix, mostly fine calcite.

Limestone usually contains about 50% CaO and 2.5-3.5% MgO. The triangle is 3.7-3.8, the water absorption is ≤0.75%, the bending strength is ≥ 10.0MPa, the gloss is about 60, and the density is 2800kg /m3.