Well... My grandmother's clan is turkish-tatar (Bucharin). First appears in books in 1495 ad, however on their tamga (coat of arms) they had a star of david. As far as I remember according to Baskakov it was supposed to symbolize that they descended from jewish turks (khazars) and therefore already existed as a clan around V-IXth centuries.
There are in total 29 clan that are attributed to be "khazar" clans, all with the six point star in their tamgas.
However this theory, like all "jewish" theories on why is this symbol appears here and there need to be weighted against another fact - as a "seal of Solomon" hexagram was in extremely wide use, by mystics of all religions, and even not only by mystics, for example in Islam:
http://www.mfa.gov.il/MFA/MFAArchive...playMode=print
or in Christianity:
http://www.nork.ru/burg/seal.html
So it's actually a very common islamic/christian ornament. Now on the other hand specifically for european swords hexgram was a very popular symbol of smiths, I think it's symbolized unity of fire and metal or something like this (I hope to be corrected).
On the other hand sometimes even through the most simple explanation would be to interpret is as an "islamic symbol", it's actually "jewish" - mints of Seymur, or Georgian/Armenian/Ethiopean (in the latter case - more based on mythology than on facts) kings symolizing their jewish descent (while in case of Tbilisi mint on the surface it appears as if they are merely copying late Abbasid's coins) or even later minted coins in typical islamic countries, sometimes actually are "jewish" in origin.