The human bone cemetery ornaments are worn on various occasions – but mainly within Tantric dance. This is part of the wrathful costume worn by the male and female yidams. It is also worn by some of the joyous yidams – and by yogis and yoginis during tsog’khorlo (gana chakra – Vajrayana feasts).
Ngak’chang Rinpoche comments:
Sadly it is extremely difficult to obtain ru rGyan now because many have fallen into the hands of collectors and museums. Although museums serve to preserve such treasures of Vajrayana – they also take them out of the rightful employment. Fortunately we have been able to obtain an old set which we shall have reproduced for practitioners. There are still crafts people in India and Nepal who are well capable of copying old ru rGyan – so all is not lost. It would be marvellous if museums were to allow the Vajrayana implements in their collections to be copied – because the actual items are needed if reproductions are to be made – as the crafts people do not work well from drawings of photographs. During the first spread of Buddhism in Tibet the ru rGyan were common and many tantrikas owned their own sets of ru rGyan. We hope to re-establish this tradition within the Aro sanghas as well as the tradition of the vajra weapons.