This is a big 600 gram plus chunk of Scottish smokey quartz crystal. It has a mica schist material on the outside but if you were to crack this open it would be 99% quartz. 
This crystal came from the mountains near Aberfeldy back in May 2024. We have only made one trip so far this year. This material is from halfway up a mountain where we pick it from amid the scree and rubble. There are several TikTok videos of us hunting for Scottish Smoky Quartz if you are interested.
This is a good wholesome chunk of grey smoky I see dark patches under there but it will need a real lapidary artist to get to the good stuff.