How do I recreate gem behavior from downwell?

Here is an example from the game if you haven't seen it:

I could use some help to break it down what the gems are doing and why do the look so nice and smooth when moving.

I just love how bouncy they are especially when you destroy a gem vein and the room is filled with the gems.

Currently I have the items as physics objects w/ 100% elasticity and when they hit the ground they lose 20% of their elasticity. It still does't make them look right at all...

You can use the "linear damping" property to make the gems more floaty, also you can improve the bounce by giving the walls an elasticity of 1.0 as well so bouncing won't lose speed. You could also tweak the gravity as well. Making the gems have a circle collision could make the bounces less jarring. One last thing I noted is the gem would be attracted toward the player, which you can do by applying some forces.