Kyanite - a mineral under great pressure - tells its story
Hi I'm the rectangular blue crystal you see in the image and my name is
I am a very useful mineral and form under high pressure deep in the earth.
Where pelitic rocks (like shales and slates) are metamorphosed (buried,
cooked and squeezed but NOT melted), my presence tells geologists
the temperature depth and pressure that was needed to form the rock I am
originally found in.
I have two friends with the same composition Al2SiO5
we never meet because we are formed under different conditions...
If you find me Kyanite then the rock was formed under
If you find my friend Sillimanite then the rock was formed
under high Temperature
and If you find my friend Andalusite then the rock was
formed under low Temperature
I am quite a useful mineral because I am quite hard and can handle high
I'm used in the porcelain of false teeth, to hold the diamond dust
together in cutting and grinding wheels and as a rare blue