Shiva Purana
अधमं चणमात्रं स्यात्प्रक्रियैषा परोच्यते । शृणु पार्वति सुप्रीत्या भक्तानां हितकाम्यया १५ ।
O Pārvatī, lovingly listen to this from a desire for the benefit of the devotees. The meanest of Rudrākṣas is of the size of a gram according to this excellent classification.
english translation
adhamaM caNamAtraM syAtprakriyaiSA parocyate । zRNu pArvati suprItyA bhaktAnAM hitakAmyayA 15 ।
hk transliteration by Sanscript