Feldspar is abundant in Earth's crust, making it a common mineral in many rocks.

Earth's Crust

Feldspar comes in different types, important for classifying and identifying rocks.

Varieties

The term 'feldspar' is often used in geology and earth science contexts.

Geology Use

 So when I first looked at this, I was -- I thought, gee, this is like a little treasure trove here. I couldn't believe it, and I'd go around dissecting the little bits out and making photographs of them. Here's what most of the sand in our world looks like. These are quartz crystals and feldspar, so most sand in the world on the mainland

Gary Greenberg: The...

 like these are quartz crystals and feldspar so most say on the world on on the mainland is made of quartz crystal and feldspar it's the erosion of granite rock so mountains are built up and they erode away by water and rain and ice and so forth and the become grains of sand there's some stand that's really much

The beautiful nano...

 has been exposed by the passage of the river you can see it there it's quite coarse-grained if you look closely you'll actually be able to see coarse quartz crystals will be feldspar and