I have worked with a material called true-stone or gem-stone made for pen turning, It's about 80 percent pulverized stone and the rest is a synthetic base I think its acrylic or a similar material. if it's more the look you are going for than it being real stone. it would be much more durable in this application than natural stone. Especially if put on a backer material. I have actually been interested in jade hones for a while and if you still have them might be interested in buying them from you. if you are interested PM me and we can talk more.
Here is a link to a site that has the Jade Gem-stone Gemstone Pen Blank-Imperial Jade, 7/8 x 7/8 x 5 1/2 [PBGem-ImperialJadeOS] - $11.99 : Arizona Silhouette inc. - Suppliers of Eye Candy, Proudly Offering Exceptional Products and Resources for the Wood Turner The thing to consider with this is wether it would be big enough for the scales you are looking to have made at 7/8 an inch by 5 1/2 it would have to be a smaller razor they where going on.