When you bring house a Panna Stone(Emerald Stone) set in ring/Pendant you should Immediately dip it in pure desi ghee in a glass or steel bowl then on a Wednesday morning before 7.30 AM take it out from Ghee and wash it with Ganga Jal used with sappron and wear it after chanting the mantra of Budh. 

As per Hindu Astrology Panna Stone(Emerald Stone) is the Gem of Mercury i.e., The mantra for this Planet is Budh “ Om! Braam Breem Broom Sah Budhai Namah”. This should be chanted 108 times in a single sitting on a onyx mala of 108 beads. 

If we talk about emerald in hindi then we find the name like Panna.

Panna Stone