Dear Skola,
I'm sorry. I am not trying to advertise or anything. I am looking for information for this item too and I found out that the blog has quite useful information about it. At the same time, I found out that the discussion on this thread regarding Jamaican stone is quite inconclusive. Thus, I provide the forum with the link.
My intention is just to share. Nothing more. I am sorry if this is misunderstood.
Thank you.