Best Answer - Chosen by the AskerHey, bro,
answering your question, It depends what kind of gemstones you want to buy.
But, Generally in the Streets from Jongno 2ga to Jongno 4ga(I'm sure you know where it is), You can find many shops there.
They are mostly wholesellers as almost 80% of gem currency.
I think you can buy a same thing for the budget price, compared to another streets where there are many jewleler's : Namdaemoon, Gangnam, Etc.
Jongno is the best, and Namdaemoon may be the next.
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