I have never used stone tiles before these tiles are 12" sq approx. and about 10mm thick. My question is could I use a good tile adhesive or should I use an alternative adhesive, these tiles can be used on walls or floors.
I don't understand part of your question - whats the difference between a good tile adhesive and an alternative adhesive?
Use a single part flexible rapidset addy and if the tiles are remotely translucent use white - grey will show through. Stonefix is good and reasonably priced. Keraflex is excellent but a tad expensive. Don't use the tubbed stuff from the sheds.