Ann: Clarification on Drilling - Update, page-84

True, the LiO2 will vary in spodumene . It’s why I’m not really a fan of reporting % of spondumene crystals as simply put they are not like sulphides.
Sulphides ( such as Bornite,Chalcopyrite,Pentlandite,Galena etc) have simple crystal structure ( cubic) so bond in many ways easily with consistent known element proportion. ie Bornite is 63% Cu.
Spodumene is part of group called Inosilicates. The crystal structure is composed of single chain bonds and so develops as ‘threads’.
As a natural result of this the crystal lattice can break down with effects such as impurities, ph ,temp etc
So spod crystals can have anything from say .5% up to 8% lithium content.
The colour variability is also part of other trace elements that bind well in the LiAl structure. So for eg green spod is result of trace iron which happily trades place with some alumina without causing crystal lattice breakdowns, so we can get large crystals.