We used recycled silver 925. (92,5% of silver + 7,5% copper)
We sometimes don't put the mark 925 on rings because it can damage the piece. We don't use lab marks because every ring is made to order and we can't travel 4 times from and to the lab and pay money only for 1 ring. So if you need a confirmation of metal, you can take it to the lab and they will prove that it is silver.