Once Lord Shiva was in deep meditation and the Ma Parvati was busy in looking after him. The little Ganesha felt left out and started crying for the attention of his dear mother. When Ma Parvati heard his cries she was perturbed and ran to pick him up but he ran and ran in the process he covered the earth 108 times.
Finally, when Ma Parvati caught him she found that the little child was perturbed and pained so she asked her what is the matter – he narrated his pains and told Ma that he was considered worth less – on this Ma Parvati gave him a blessing that he will be worshiped in Idols made of Panna Stone – none less and people will wear Panna Stone to appease him. From that time on words the Idols of Lord Ganesha are made of Panna Stone or Markat Mani (Sanskrit).
His devotees wear Panna Stone in order to appease him. Panna Stone is gifted to the children with prayers that the protective shield of Lord Ganesha will remain with them.
It has been observed that those who wear a Panna Stone are blessed with love, wealth and family happiness.
You should always get the Panna Stone Abhimantrit before wearing it.