The description of this golden idol is found in the footnote of the novel 'Pandurang Hari' by William Hockley. Emeralds were fitted in the eyes of this idol which was made purely of gold and its whole body was decorated with diamonds and rubies.
The above info is mentioned on page 33 of the book titled "Shaniwar Wada - The Official Residence of Peshwa" written by Professor P. K. Ghanekar.
Please check our Facebook page at https://www.facebook.com/historylogy for the latest updates and giveaways.