ज्ञान-रत्न gyān-ratna

ज्ञान gyān (sanskrit)

Knowledge directly taught by God.

रत्न ratna (hindi)

A gem, precious stone.
The most outstanding individual of a class.
The pupil of the eye.
(in comp.) Anything valuable or desirable, any precious thing, anything excellent or best of its kind (e.g. strī-ratn, 'a pearl of a woman').