Is feldspar rare?
What is feldspar made of?
Feldspar and quartz make granite
Feldspar often combines with another rock called quartz. That makes a much harder igneous rock called granite. Granite was very useful to people. For example, in ancient Egypt, artists carved statues out of granite. People also use granite for buildings.
Feldspar and pyroxene make basalt
Or, if feldspar gets in contact with another rock called pyroxene, those two rocks combine to make basalt. Since the Stone Age, people have used basalt for grindstones. Basalt is a very hard rock too. One of the earliest trade goods was basalt for grindstones, carried down rivers or on donkeys.
Feldspar becomes kaolin clay
When feldspar is in contact with wind or water, the wind and water gradually grind the feldspar down into tiny grains that become one kind of clay called kaolin. Kaolin is the extremely fine, white clay that Chinese porcelain is made of.