What 999 silver actually means
999 silver is 99.9% pure silver by weight. The remaining 0.1% is trace elements left over from refining, not a deliberate alloy.
999 is a fineness figure. It says that out of every 1,000 parts by weight, 999 are silver. The last part is trace material left behind by refining rather than something added on purpose. That is why 999 is often called fine silver.
Alloyed silver is a different thing. Metal is deliberately added — usually copper — to make the piece harder and more resistant to bending and scratching. The trade-off is that the added metal is what drives tarnish, and the piece is no longer priced purely on silver content.
Why purity matters to the price
A piece sold by weight is worth the metal it contains. At 999, the metal value of a 10 gram coin is the day rate multiplied by 10 grams multiplied by 0.999 — a figure anyone can check against the published silver rate.
Where 999 is the right choice, and where it is not
For coins, bars, murtis and keepsakes, 999 is the better metal: maximum silver per rupee, slower tarnish, and a piece whose worth is legible.
For anything that takes daily mechanical stress — cutlery that gets pressed against a plate, a clasp, a hinge — fine silver is soft and will mark and bend more readily than an alloy. We say so on those pieces rather than pretending purity solves every problem.