Marble feels like Marble
Natural Materials have a wide variety of feels and weights.
Be careful about drops as any natural material will more easily fracture and that could split a ball in two.
They are also heavier than the typical practice ball like the stage ball.

Control Points

Wood Balls are a good practice ball and they are natural. I also like LedraPlastic balls and any Rubber Stage Ball. Try a wide variety of balls till you find your favorite.