what if the metal turns black >>>>

I purchased the acid for testing silver…I know to use a file and go under the surface of the piece…however, I’m a bit fuzzy on a few things…
i.e. how long do I leave the acid on??? I know a creamy result is good… and a green is bad…however, what about black? I read somewhere that it means that the piece is the level of “coin silver” WHAT THE HECK DOES THAT MEAN, AND DOES IT MEAN THE PIECE CAN BE SOLD FOR A PRETTY GOOD RATE??? UNLIKE SILVER PLATE, WHICH UNLESS THE PIECE IS OF VALUE - BECAUSE OF IT’S ANTIQUE VALUE - IS BASICALLY WORTHLESS!!!

dont know what asid you use. Mine say red=silver and it takes a split secund.
Remain same colour = not silver. Reaction a split second.
Then ou remove - no reason to wait. Te assid is no longer active.
Black you have left it to long time on silverplate.

Hello silverbug99,

I apologize for not noticing your post earlier.

I would purchase a different acid – one made specifically for testing silver. Please read on…

Testing for Silver Content

The identifying of a questionable piece of silver empirically is less invasive than performing an acid test. A 10X loupe is basic equipment for an appraiser. If by observation an object’s silver content cannot be identified, the following method can be employed…


10X loupe, silver testing kit (includes acid and testing stone) contenti.com, 401/305-3000
Magnet: hardware store
Container of water with baking soda added to neutralize testing acid
Cotton balls
Acid gas respirator, safety goggles, nitrile gloves: leonardsafety.com, 401/434-4660

CAUTION! Always wear an acid gas respirator, safety goggles, and nitrile gloves when performing this process, and work in a well-ventilated area. Use extreme care when handling silver testing solutions; they contain acids. In case of skin contact, flush with large amounts of water then treat the affected area with baking soda. If the solution is swallowed, contact the national poison hotline is 800/222-1222. In case of spills, treat with water and then baking soda.

  1. Rub an inconspicuous area of the object over the testing stone (e.g. the underside of a foot of an open salt) – press firmly, leaving a large, thick visible deposit, preferably a line 1”–1.5” long. It is possible to test directly on the piece in question with the testing solution; however, this will lightly etch and dull the surface.

  2. Add one drop of the acid solution to the testing stone or scraped area on the object. Wait approximately 15 seconds to notice the color result, then dampen the testing stone or object with a neutralizing cotton ball and rinse with clean water. The color reaction of the solution with the metal indicates the following:

Bright Red = Fine Silver (.999)
Dark Red = Sterling or Coin (.925 or .900)
Brown = Silver (.800)
Blue = Copper
Green = Brass
Turquoise = Nickel

Magnets will only be attracted ferrous (iron) metals, such as carbon steel knife blades.