Yes, but a pound of gold is only 12 Troy ounces and considerably less than a pound (16 av. ounces) of lead. For the same reason, a pound of feathers weighs more than a pound of gold.
Except density changes with temperature. Although apparently not enough to matter in this case.
What weighs more? Jupiter or a brick?
How big is the brick?
That depends… how long is a piece of string?
And how close is it to a black hole.
And is the gravitational pull of the black hole working against the friction asserted on the brick by a special treadmill rolling away from the black hole?
If the brick is in orbit around Jupiter, they weigh the same relative to one another. Jupiter pulls on the brick just as much as the brick pulls on Jupiter.