If it is a Translucent Ark, I have had several that look just like that, you can get it whiter by soaking it in a 50% solution of Simple Green or Awesome and water. Years of Oil use penetrate the stone. It can take months to completely remove all the oil. Awesome is a bit more aggressive.

I have several stones soaking, some for months in glass rubber sealed pasta jars. The seal keeps the water from going rancid, I change the solution every few weeks/months and scrub the stone to remove oil that has come to the surface, with hot water and dish soap. Hot water and solution will speed up the initial surface oil removal.

The solution will get darker with oil release. Once the solution does not change color, all the oil that is coming out, is out.

The oil does not affect the performance of the stone, but it gets rid of any rancid oil smell.

There is much written about Ark Translucent and Surgical Black finishing for razors, they are unique edges, you can also tailor the stone face to get finer edges on your razor. The smoother the stone face the slower and finer it will cut, you can add paste or Nano git sprays to improve or tailor performance and shaving edges.

Prep both faces differently to produce an Ark finishing “Progression”,