'Śrī Rādhā-Ramaṇa is the deity of Śrī Gopāla Bhaṭṭa Gosvāmī, the recipient of Śrīman Mahāprabhu’s mercy. Śrī Bhaṭṭa Gosvāmī initially served and worshipped a śālagrāma-śilā. Once, he intensely desired to decorate his śālagrāma, to seat Him on a swing and sway Him back and forth, and to serve Him in many ways like a deity. “If only He had arms and legs like a deity‚” he thought. Prabhu is very kind to His devotees. To fulfil the desire of this bhakta, He transformed Himself that very night into the attractive threefold-bending form of Śrī Rādhā-Ramaṇa. Śrī Bhaṭṭa Gosvāmī decorated Him with many ornaments, swung Him on a swing and offered food preparations with great affection. If one has darśana of Śrī Rādhā-Ramaṇa’s back, one will see that it resembles a śālagrāma-śilā. Although the deity is only twelve finger-widths tall, He is very attractive. Śrī Rādhā-Ramaṇa’s lotus face is like Śrī Govinda’s, His chest is like Śrī Gopīnātha’s, and His lotus feet are like Śrī Madana-mohana’s. By taking His darśana, one receives the benefit of taking darśana of these three deities.
'According to the book Sevā-prākaṭya, Rādhā-Ramaṇa manifested from the śālagrāma-śilā in saṁvat 1599 (1543 AD). His abhiṣeka took place on Pūrṇimā in the month of Vaiśākha (April–May) that same year. There is no deity of Śrī Rādhā with Rādhā-Ramaṇa, but a gomatī-cakra is worshipped on the altar to His left. According to an injunction in Śrī Hari-bhakti-vilāsa, a gomatī-cakra is to be worshipped along with a śālagrāma-śilā.
'Adjacent to the temple of Śrī Rādhā-Ramaṇa, to the south, is the samādhi of Śrī Gopāla Bhaṭṭa Gosvāmī and the place where Rādhā-Ramaṇa appeared. Unlike other deities, Śrī Rādhā-Ramaṇa never left Vṛndāvana.'
--Srila Bhaktivedanta Narayan Goswami Maharaj, _Vraja Mandal Parikrama_
You can see this and many other photos of the beautiful Sri Radharaman Deity at the Facebook