Blue is my favorite color. It has been used in art throughout history, for instance in Middle Age cathedral windows.
Blue is also my favorite color too! That's really cool that it was in windows!
Yup, another use of it was Chinese artists in the 8th century, for porcelain.
I've seen those before! They are really expensive now.
They are actually used as artifacts in archaeology, probably because they are preserved really well.
That's true... I wonder why they were so well preserved.
Apparently stone tools from 3.3 million years ago are discovered, so we can learn a lot about the past!