No it can not be precious metal because precious metals are weighted by troy ounces.? A troy ounce = 31.1 grams. A regular ounce = 28.34 grams.? 7 grams is closer to 7.085 grams of a regular 1/4? ounce? than 1/4 ounce troy at 7.775 grams . Kind of hard to imagine any precious metal being corrodated like that. Also weights are exact not "close" to 7 gram for precious metal bullion.
There is no scale here so as a guess a lead weight
George