If you want tip-top yet practical material for pieces, it's mammoth ivory, I don't include gold, diamonds, etcetera.
Ebony/boxwood is fine for wood, as is red sandalwood/boxwood, and rosewood/boxwood. There are others, like purpleheart, that rarely get used for pieces but seem to work well enough.
Boards can use many fine materials from stone to wood and be very practical. The variety of woods used for boards is impressive.
What is the best, highest quality for chess boards and pieces?