The pattern is the script called "Square Kufic" (a google image search +mosaic reveals many wondrous examples) and the arabic form of al-Khwarizmi is الخوارزمي
The kufic letters are fairly abstract but look for the verticals, there are 9 letters (last 2 are joined, I think, I cannot read it either just looking closely)
ا A
ل l
خ kh
و w
ا a
ر r
ز z
م m
ي i
