Bone Craving Mining Related

Hi any ideas on this one ? It is a craving showing a Wheel Tower with the Hammer and Sickle emblem to one side on the other side is a Jack Hammer with a Russian Star (symbol of Communist ) above a coal seam see pictures this is BONE not ivory . Would love know the story behind it , ie why it was made ,who by ? there must be a tale somewhere .Any information would be of interest Thankyou.
I was out and about sunday gone and looking at my local Car Boot found the above item what a great find