Bluedust has now moved mining and processing equipment to the property.
The gear includes a Bourevestnik, three 30-tonne dumpers, 30-tonne and 46-tonne excavators, a 50-tonne excavator with a centric ripper, Foton 558G and 908G front-end loaders, two mobile sizing screens and 16-foot pan plant.
It has also recommissioned Tango's 14-foot and 16-foot pan plants.
This work will allow Bluedust to prioritise each area that has been identified with diamondiferous ROM (run of mine) and tailings and allow for the development of a comprehensive project development plan, Tango said.
It is also assessing the NI 43-101 inferred resource from 2014 and several other priority targets.
Oena is 8,800 hectares and covers a 4.8km wide strip along a 15km length of the Orange River.
Tango shares in Toronto were unchanged at C$0.035.