BLACK ONYX RING SILVER SEMI-PRECIOUS-This ring is made of silver with black onyx, which has been polished well to make it shine. Please indicate size while ordering or send us an e.mail. To take the size, simply wrap a thread around your finger. Measure the length of the thread to get the ring size. Sizes in respect to thread length are : Size 5 - 4.932 cms, Size 6 - 5.186 cms, Size 7 - 5.451 cms, Size 8 - 5.715 cms, Size 9 - 5.966 cms, Size 10 - 6.233 cms , Size 11 - 6.497 cms , Size 12 - 6.751 cms , Size 13 - 7.015 cms.