Onyx

Onyx is a calcareous rock with a very fine grain and many veins running concentrically to each other. It originates from underground water or spring water, which are rich in calcite. Overtime, the precipitation at the mouth of the spring builds a crust of calcite crystals. The variation of onyx pattern and colour are caused by the amount of impurities and differences in water flow rate. Onyx is strongly banded, crystalline, and translucent which coloured from brown to yellow.