Clue in the arrowword. Virtually Black ?N?Y I just cannot think what it is? Onyx is the only one and that doesnt fit. Thank you to the clever posters who will no doubt get it instantly :D
Line of hire cars (4,4) _A_I
Straightfaced (7) _S_D_ _ _
The length of (5) _ _ _ _ _
Valuable heavy timber for furniture making (8) R_A_W_ _ _
Sturdy Canines (8) B_D_D_ _ _
Thank you...