Good day, qalamites.

I am seeking for an example of an abjad which uses vowel diacritics
(optionally, of course) but does *not* use matres lectionis.

Did such a thing ever exist?

As far as I understand, none of the modern abjads (Arabic, Hebrew, Syriac)
fits the description: they all use consonant letters to spell vowels.

Thanks everybody in advance.
_ Marco