Solution:Concept: Pyrargyrite is another name for ruby silver. It is a unique mineral whose chemical composition includes silver. One of the rare silver-bearing minerals that can display transparency is pyrargyrite.
Additionally, this mineral has two quite different behaviours. the other as an opaque, dark metallic grey shape, and the first as transparent, deep red crystals. When backlit, some of the opaque, metallic-looking specimens will nevertheless display a faint red colour.
Ruby silver is sensitive to light. The mineral's transparency will darken and it will become darker when it is exposed to bright light for an extended period of time. A dull, dark film that forms on crystal faces as a result of the prolonged exposure of ruby silver may typically be removed by brushing the specimen with soapy water.
It is chemically represented as Hence, the correct answer is option 4.