Kyanite

["Madan Subramanian" <madans at hathway_com>]

This question is for geologists or rock and soil experts:

I have come across a rock called Kyanite with a guy who deals in minerals.
He tells me this contains about 54% Alumina and the rest is silica.
He also says it does not change the pH of water and alumina will not leach
out into water but has no idea if it is safe to use in planted aquaria.
Any information on weather it can be safely used in planted aquaria or
otherwise will help me a lot.
This rock is a beautiful brownish red in colour and I was sold when I saw
it.

TIA

Madan Subramanian
Bangalore, India.
madans at hathway_com
madans at satyam_net.in