Granite bedrock

Granite was formed by crystallising from molten stone. Its formation took millions of years, because crystallising deep underground is significantly slower than in the lava that burst on the surface. That is why the mineral grains are so large that they can be seen with the naked eye. Granite consist mainly of potassium feldspar, quartz, and mica. The potassium feldspar gives the rock is reddish colour, the quartz its hardness.

Although granite is a durable rock, it does break and crumble in the right conditions. Over ten kilometres of rock has crumbled away from the top of Alkkianvuori. Weathering slowly crumbles all the stones on the Earth. When given hundreds of millions of years of time, it can even out the greatest of mountain ranges.