Aloha members and moderators,
I am hoping that someone in this forum can help me.

I have accepted the responsibility of cleaning the Black Star Galaxy Granite "Holy Water Fountain" at our church. I have read everything I can find about cleaning granite, and although it has all been helpful none of it addresses this particular situation. The fountain has built up limescale and hard water deposits on the upper shelf where the water flows from the top basin into the bottom basin. l I have yet to find anything to remove the limescale/hard water deposits that won't damage the granite. Additionally, the oil used for baptisms leaves a film that I can't remove without detergents that are difficult to rinse off. The fountain needs to be cleaned, emptied and refilled at least once a month. Despite my best efforts and more than an hour of rinsing and cleaning the granite never really shines like new, and the limescale looks awful.

Any advice will be greatly appreciated (and surely rewarded by our Heavenly Father).

Mahalo (Thank you),
Clueless