Had used the http://hcl89.byethost10.com before to clean some of my toilet tiles as well as the grouts and so far the grouts have reverted to the original colour when i first bought the tiles. Very good product if you want to refurbish your grouts or tiles
No its not a natural pattern, its either ingrained dirt or it was etched by some sort of acid
You can use something called HCL89 to remove the ingrained dirt or the etch on the stone
You can usually get it from http://hcl89.byethost10.com or http://hcl89.atwebpages.com
It also protects the stone so that the stone is always kept new like
Take care
I too have some mould in my room area and the HCL89 product from http://hcl89.byethost10.com looks rather promising and i also intend to use it as i feel that the mould in my room area is spreading, hmm
Had the same experience as you when i used the HCL89 from http://hcl89.byethost10.com as well. I was looking for something to clean the tiles on my kitchen, and i used it, it removed all the grime and dirt with relative ease
This is due to mould. You can use something called HCL89 to remove it, it will remove the mould as well as well as any stains. You can get it from http://hcl89.byethost10.com or http://hcl89.atwebpages.com Take care