According to the story of Abraham after he settled Hagar and Ishmael in Bakkah (now known as Makkah) he and Ishmael set out to find a cornerstone to build the first house of worship to God. In all of the area there was no stone to be found. Ishmael went in one direction and Abraham another. When Ishmael came back he saw that his father Abraham was already building the house. He asked his father wear he got this cornerstone to start construction since he had searched everywhere and couldnt find one. Abraham told Ishmael that God sent it down from the heavens.
Deviant Arab tribes set up false gods at the site many years later. When Islam came, the Prophet Muhammad had all of the idols destroyed. Since then, in the history of the kabbah, it has been destroyed and rebuilt in various wars… but the the cornerstone has always been protected and eventually was encased in glass at the site of the kabbah.
It does not serve as a item or idol of worship… it is merely encased there as a historical monument that was left to use by Abraham. The reason we pray in a circle around the kabbah is simply because that is how Abraham and Ishmael prayed and dedicated this House of Worship after they completed its construction.
In Islam God cannot be represented by anything on earth, in the heavens, under the earth or any part of creation. God is Unique from Creation and seperate from it. Thus nothing human, animal, stone, wood, earth, stars, moon, can be worshipped or set up as a charm or center of worhsip or a partner with God.
We dont worship the stone… its merely a historical monument that is not to be moved from the site that Abraham built.
BrJimC