All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
Apparently – and Allaah knows best – there is no harm in using rice to make jewelry as described and this does not consist in degrading for food or playing with it. The scholars permitted using food for purposes other than eating in case of need and benefit.
Shaykh Ibn Baaz was asked about using henna mixed with egg yolk to condition the hair. He replied, “There is nothing wrong with that if it is of benefit. Using henna mixed with egg yolk or other permissible substances is harmless if that is good for the hair by helping it grow long or making it smooth or something else, or by helping to keep the hair and prevent it from falling out.”
Ash-Shawkaani highlighted a general rule in this regard stating, “The basic principle concerning everything is that the owner is entitled to do whatever he wishes with his owned property since Allaah The Exalted says (what means): {It is He who created for you all of that which is on the earth…} [Quran 2:29] If the property is among the substances that exist on earth for the benefit of mankind, then it is permissible for them to own it and to do whatever they wish with it unless sound evidence removes the principle rule; in this case, it should be referred to and practiced.”
However, if you can find an alternative substance to food grains to make jewelry, that would be better.
Allaah Knows best.