Thanks to someone else for this info below, useful info.

Veldspar = 100% Tritanium
Scordite = 67% Tritanium, 33% Pyerite
Plagioclase = 50% Pyerite, 25% Tritanium, 25% Mexallon
Pyroxeres = 82% Tritanium, 11% Mexallon, 6% Pyerite, 1% Nocxium
Omber = 42% Tritanium, 42% Isogen, 16% Pyerite
Kernite = 50% Mexallon, 25% Tritanium, 25% Isogen
Jaspet = 40% Mexallon, 20% Tritanium, 20% Pyerite 20% Nocxium

Stacked module effectiveness:
1st module = 100.000%
2nd module = 86.9119842%
3rd module = 57.1037996%
4th module = 28.2469117%
5th module = 10.5988834%
6th module = 2.9989473%