It's Pyrite also known as "fools gold" because of it's color being a brassy gold.
Answer:
Natural vs synthetic materials
"Natural" products are made from natural resources, like wood and sand. "Synthetic" products are also made from natural resources. For example, the synthetic material plastic is made from petroleum, which is pumped out of the earth
From my 40 years plus as a geologist, I would say that it is very difficult to find a semi-sedimentary rock and either I have observed sediments, often quite compact but not half way towards being a sedimentary rock, still only a sediment.
Mountains, lakes, rivers, caves, and valleys
It is a product of the Old World.
