Answer:
Slate and Analcime minerals are formed when shale and basalt are exposed to low grade metamorphism.
Explanation:
As a result of metamorphosis of clay, shale and basalt a fine grained rock is formed that is unique slate texture. Slate is formed by low grade metamorphosis i.e low temperature and pressure.Slates are the older rocks perhaps in some places the recent formation can also be seen. It can be of various colours like black, blue, purple, red, green and grey.
Dark colour of the slate is due to the presence of more carbon material. Analcime is a white, colourless or can be grey tecto-silicate mineral. It consist of hydrated sodium aluminium silicate in cubic crystalline form. Analcime is similar to that of zeolite mineral with which it is sometime classed
