[Lenor]

Gris I wish I could help, but truth be told I honestly haven't a clue what you are referring too about 'weathered black basalt'; If you could be a little more specific :/

Very true about shadowing, I did miss calculate also that without seeing the picture up close It is hard to tell being as it probably looks different on my computer.

Although in contradiction, I have a couple friends who have no problem's mimicking shadow into a realistic look.

I wish I could help ya more, but most likely your own perspective would be the best. :/