Thank you for your comments Sirs.
Here is a clearer picture taken just today as they handed me the sample. Sorry for I have mentioned above that the picture is more than 7 kilos, that picture they have given me above is only from the sample, not the 7 kilos, they keep the 7 kilos.
I don't think its almaciga or wood resin, its hard, its really a stone or a portion of a rock. We doubt that it is a gemstone, only we don't have idea about how gemstones look like when still unprocessed. They found also a samurai (sword with Japanese markings) from that same site, I hope I can get some photo also of that said samurai.
The picture with file name "with flash2" is taken with a camera's flash turned on, while the picture with file name "wout flash2" is taken when flash was turned off.
Again I am hoping that you will share your ideas.