Snuff Jar/Bottle/Box???

I recently purchased this item because I am absolutely amazed by the artwork, design and intrigued by the over all beauty. Please someone tell me what it is , when it was made/used/popular and what its made of, it appears to have the coloring of marble as well as the weight but then again it also looks like an acrylic or plastic material too. The 'metal' covering it is uniquely carved and detailed. I have asked a few antique type places and they all refer to it as a snuff box/opium box. I really would like as much information as I can find and possibly even a value. I have been researching for awhile now and have not been able to find anything at all that resembles this.
Thanks for any information that anyone can share with me.
Jacqie