It’s not so much the reflectivity of the stone, it is the smoothness.
When you burnish with a hard edge, like a large carbon, kitchen knife, cleaver or wide plane blade, you will feel any rough spots. You can also hear them.
Keep working those spots until the whole stone face is smooth. Then try a razor on the stone, you want honing performance, not necessarily the shiniest stone.
Keep the ladder on the right wall…