In the absence of an acid testing kit, use what you have in your
w/shop to do a comparative test to establish wether its sterling or
not.
- polish a corner, do likewise with sterling and compare the colour
in daylight.
Nickel brass will have a yellow tinge. Sterling will not.
- cut 2 identical sized strips say 1/4in by 2 in one in the unknown
metal and one in sterling. mark the sterling with say an S stamp!!
Place on your charcoal block and heat to a red colour. Watch how they
oxidise. Quench in water and compare via a bend test. The sterling
will be softer.
If your purchase is sterling a good find!!.