Even some of the blackest looking tourmaline can be classified as green when examined closer.. but what could be happening in the images above unless these where simply unearthed.. one cant tell.. But it these had just been laying on top of the soil for years.. the tourmaline would start to age, weather and turn the deep dark black seen here. Care must be taken if one is to attempt to remove these exposed wands/crystals. Typically when we explore the gem mines we end up wit broken bits from strands like this because whom ever extracted them didn't or doesn't care.