What an elegant mosque @tomidiwirja! The color white with a few accents truly enhances the religious experience.
When I felt the surface of the pole, it turned out that this pole was made with a cement base and the surface used small pea stones which using a certain technique were directly mixed with a gray material.
This type of architectural surface application is known as pebble washout finish. Small stones are mixed with wet cement, exposing them when cured. Though they might differ in their aesthetic outputs, this artistic style gives walls (and columns) a more textured feel. Hope that helps. ☺️
Thanks for Elevating Architecture and Design with Hive!
Thank you again, thank you for the information. I understand more about the design and architecture of this mosque. My knowledge has increased.