This is a incredible green Montana sapphire that color shifts to a almost grey blue in other lights. The videos I used show the stone in many different lighting's to really showcase it's beauty. The luster is excellent and in certain lighting's this stone truly comes to life. It was cut by Mike Soebbing and he always does a fantastic job. The dimensions are 6.63mm and this beautiful piece of Montana has not been heat treated. With VVS clarity this is a perfect engagement ring stone.