"Graphite" is an excellent way to describe it! and that clinches it.
It's made from a naturally occurring mineral called Shoushan stone in China- and easily recognized by its characteristically greasy feel and softness when scratched with a needle. Normally it's cre***** ***** marbled with reddish ocher and traditionally used for carving signature seals.
Your piece has been further enhanced with a red dye to give it a look of rose quartz, one of the most prized hardstones of the orient. Here's a rose quartz recumbent horse that just sold for $3000. Quartz is harder even than glass, so ones hat goes off to the carvers of these especially in the days before diamond tipped cutting tools.
The carving on yours shows some pleasing fluidity and gesture but the lack of detail leaves much to be desired. Strictly speaking, in the pantheon of mythical Asian beasts, this is a chilong, a small hornless dragon always recognized by his forked or double tail. Chilongs are a highly popular and ever-present feature of fengshui as they are believed to protect the home from fire and winds.
I don't think yours is particularly old, probably last quarter of the 20th century or newer, so not old enough to have gathered any premium for being antique.
It would sell on line (eBay etc) in the $20 - $40 range. So $80 full retail/replacement value.
Hope this is useful info!