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