If you are willing to go with stone shapes and fragments, and think some distance "out-of-the-box":
Cut slivers of granite with a wet tile saw.
Then cut the slivers into smaller shapes/strips with a diamond blade mounted on a Dremel tool or flex shaft, and/or pulverize the slivers a makeshift crusher, which you could make by capping a large metal pipe and capping a smaller pipe, taking a big hammer to crush the stones between the inner and outer caps (which is a simple method used to make crushed mineral inlays)
Adhere the stone shapes or fragments onto a coarsely sanded brass tube using tinted Alumilite , polyester resin, epoxy, or thick CA glue
Then cast the granite-covered tube in a tube-in mold (such as a Fred Wissen's tube-in silicone mold), then lathe-turn it to your final shape.
Tints and metal flakes mixed into the resin could help "amp-up" the blank.
(last time I did a lot of stone carving and turning with gem smithing machines, I earned a fiberoptic sinusotomy to ream out my sinuses - better to embed, suspend, or inlay minerals).
I still do internal microsculptures in optically clear quartz, but use lots of irrigation (Waterpik), ventilation, and a respirator mask.
Just my 3 cents
Your granite is beautiful.
Best regards, Bob