Breakdown of Yüzük için bu elmaslardan ve yakutlardan var mı?
bu
this
var
there is / existent
ve
and
için
for
Questions & Answers about Yüzük için bu elmaslardan ve yakutlardan var mı?
Why is the ablative suffix -dan attached to both elmaslardan and yakutlardan here?
This is the partitive use of the ablative case. Adding -dan (meaning "from") creates the meaning of "some of" a larger whole. Instead of asking if diamonds generally exist, you are asking if there are some of these specific diamonds available to use for the ring.
Why is bu in the singular form if it translates to "these"?
In Turkish, demonstrative adjectives like bu (this/these) and o (that/those) never take a plural suffix when they are placed directly before a noun. The plural meaning is shown only on the noun itself, as in elmaslar (diamonds).
Could I just attach the suffixes to the last word and say bu elmas ve yakutlardan?
Why does the sentence use var mı ("are there") instead of a verb for "do you have"?
When asking about availability, especially in a shop or checking an inventory, Turkish relies on the existential words var (there is) and yok (there isn't). Asking var mı? is the standard, natural way to express "Do you have [this item] in stock?" or "Is [this item] available?".