Some diamonds are sent for certification once they have been polished. There are many different institutions such as the G.I.A. and H.R.D. offering certification of diamonds. One should remember when evaluating the value of a diamond, that although a certificate is an accurate opinion of a diamond's quality, the certificate does not guarantee the quality of the diamond that it is describing. Diamond certificates gained in popularity in the 1970's when large financial institutions were investing their funds heavily into diamonds and gold bullion.