'Foundation stones' in the Bible

The wall of the city had twelve foundation stones, and engraved upon them were twelve names--the names of the twelve Apostles of the Lamb.

As for the foundation-stones of the city wall, which were beautified with various kinds of precious stones, the first was jasper, the second sapphire, the third chalcedony, the fourth emerald, the fifth sardonyx, the sixth sardius,