Charak Samhita
मधुरश्च सतिक्तश्च जपापुष्पनिभश्च यः। कटुर्विपाके शीतश्च स सुवर्णस्य निस्रवः ॥५७॥
This is shilajatu. Shilajatu obtained from gold ore is sweet, slightly bitter, having color like japa flower, pungent in vipaka and sheeta veerya.
english translation
madhurazca satiktazca japApuSpanibhazca yaH। kaTurvipAke zItazca sa suvarNasya nisravaH ॥57॥
hk transliteration by Sanscript