step 1 of 7
I made diamond using ngons per tutorial @ http://www.veoh.com/collection/tutorials3D/watch/v63806802495swE4#

sources used for this step:
step 3 of 7
making crown with tube, torus, and torus knot
step 4 of 7
some work with edit arc and shell modifier
step 7 of 7
texture

sources used for this step: