In mineralogy, which mineral is commonly known by the name Horn silver and is an important ore of silver?

Introduction / Context:
This question belongs to general knowledge in chemistry and geology. Many minerals have traditional names that differ from their chemical names. Horn silver is one such traditional name, and knowing its chemical identity helps connect common names with chemical formulas and uses in metallurgy, especially in silver extraction.

Given Data / Assumptions:

• The common mineral name given is Horn silver.
• We must match it to the correct chemical compound.
• Options include silver chloride, zinc phosphate, silver iodide, silver sulfide, and lead chloride.

Concept / Approach:
Horn silver is the common name for the mineral consisting mainly of silver chloride, usually written as AgCl. It forms as a secondary mineral in the oxidation zones of silver deposits. Other silver compounds like silver iodide and silver sulfide have different common names and appearances. Therefore, identifying Horn silver as silver chloride is the correct choice.

Step-by-Step Solution:

Verification / Alternative check:
Mineralogy references and mining dictionaries list Horn silver as the common name of the mineral cerargyrite, which is silver chloride. Photographs and descriptions show a gray to greenish mineral associated with oxidized silver ore deposits. Other silver minerals like argentite (silver sulfide) have their own specific names. This consistent identification confirms that silver chloride is the correct answer for Horn silver.

Why Other Options Are Wrong:

• Zinc phosphate: Contains zinc and phosphorus, with no silver content.
• Silver iodide: A silver compound used in photography and cloud seeding, but not called Horn silver.
• Silver sulfide: Known as argentite or acanthite and has different properties and names.
• Lead chloride: A lead compound, not a silver ore mineral named Horn silver.

Common Pitfalls:
Students often confuse different silver minerals due to similar metallic associations. Remember that common names are historical and do not always follow systematic patterns. Linking each traditional name with one clear chemical identity through practice questions is a good way to avoid confusion in examinations and in general chemistry quizzes.

Final Answer:
The mineral known as Horn silver is Silver chloride.