This is a rough translation of the stone tablet brought to me by courier earlier today.

The cuneiforms of this particular tablet are far different to anything I have previously seen in my career as an archaeolocial expert.

Where possible I have given as accurate a translation as possible, but some of the words I have attempted to translate hold different meanings depending upon their intonation and context; Due to my unfamiliarity with this language, I have given possible translations for these words wherever I have encountered them. Wherever I have a word in brackets, it is a word which has many meanings depending on the context, although the general meaning should be clear to even a casual study.

Hopefully this translation will help you in your excacations Asgarnia, and as usual I look forward to seeing whawt relics you bring back to the Museum of Varrock this time!
Your friend, as always,
Terry Balando

Translation follows:

(There are some missing sentance fragments here, presumably from a stone tablet preceding this one which you have not yet discovered)

...the permanent

(exile/journey) of the people ended.
And so it came to pass, that deep in the (fiery/uncomfortable) desert, the gods (argued/decided) amongst themselves that the (fortress/home) would be the (selected/chosen) place that would (imprison/conceal) the (wealth/power).
Thus (guarded/protected) by the (unusually archaic word here, I believe it means either the sick or the dead depending on context) and (defended/trapped) by the (diamonds/crystals) of (this word is untranslatable). So it was that the gods left the four (diamonds/crystals) as the (key/secret).
(Guarded/Protected) by the (again, this word has no modern equivalent) and held by the (worthy/strong) so that the (wealth/power) might forever be (imprisoned/concealed).

There seems to be some further missing information continued onto a further tablet, but from this preliminary translation I think you may be onto something very big indeed!