Kitchen counter top - joints

[Chandu]

Have ordered 30mm black granite slabs for kitchen counter top.(along with granite sink)
Due to its length ie 9ft - vendor suggested 2 slabs each of 4.5ft.

Question I have is , Who will mount this slabs - I assume it is my Mason.
How can I make sure that slab joining/joints are fixed correctly.
What material should be put to join the slabs - will that match the color of the slab ?

[Chandu]

have found answers
- Mason will mount counter-top and sink.
- Black oxide powder should be used to fill joints between counter-top and sink

[blorebuddy]

hi
Can you please tell me where did you buy this granite sink (is it a manufactured one with slabs?)
how much is the cost?