This is a Blue Amber Free Form/Tumble Shape. It is approximately 34.9 x 23 mm ; thickness is approximately  23 mm, with a weight of approximately 13.35 grams. 
 
Amber was formed form the fossilization of resin from the pine tree millions of years ago. It is one of the lightest gems known. Blue Amber can be found in the Dominican republic. Amber has been used as medicine and money in some civilizations. Also known as Succinite. Mohs hardness is 2-2.5.