The question of whether silver or gold is “stronger” depends on the definition of strength, as the term applies differently to metals. Strength can refer to physical durability, such as resistance to scratching, or chemical stability and resistance to corrosion. Both silver and gold are precious metals, but their distinct properties determine their performance in applications ranging from jewelry to electronics.
Comparing Physical Hardness and Malleability
When considering the pure forms of these metals, physical hardness is measured using standardized scales. On the Mohs scale, both pure gold (24-karat) and fine silver (99.9% pure) are extremely soft, with values between 2.5 and 3.0. This makes them easily susceptible to scratches and dents.
Silver is marginally harder than gold in its pure state, confirmed by the Vickers hardness scale. Despite this minimal difference, both metals share a high degree of malleability (capacity to be hammered into thin sheets) and ductility (ability to be drawn into a fine wire). Gold is the most malleable of all metals. These characteristics mean that while both are physically soft, they are highly resilient to fracturing.
Chemical Stability and Tarnish Resistance
The chemical stability of gold is significantly higher than that of silver because gold is a noble metal. This means gold is highly resistant to chemical action and oxidation. Pure gold (24K) is virtually inert and maintains its luster indefinitely, untouched by air or corrosive agents.
Silver is notably more reactive than gold. Its primary sign of reactivity is tarnishing, which occurs when silver reacts with sulfur compounds in the air. This forms a layer of silver sulfide on the surface, causing the metal to darken.
Tarnishing is a surface-level change that does not affect the structural integrity of the silver underneath. The need for frequent cleaning demonstrates silver’s lower chemical stability. Gold is the chemically stronger metal due to its superior resistance to environmental degradation.
How Alloying Affects Real-World Strength
Because of their inherent softness, fine gold and fine silver are rarely used in practical applications. To achieve the necessary strength and durability, both metals are alloyed with base metals. This process significantly increases the mechanical strength and scratch resistance of the final product.
Gold purity is measured in karats. Adding metals like copper, silver, or zinc creates common alloys. For instance, 14K gold (58.3% gold) is substantially harder than 24K gold due to the base metals. These alloys can exhibit a Mohs hardness up to 4.0, a notable increase over the pure metal.
Silver is commonly alloyed with copper to create sterling silver (92.5% silver and 7.5% copper). This alloy is significantly harder than fine silver, making it suitable for functional objects. However, this mechanical improvement reduces chemical stability, as the copper content causes sterling silver to tarnish more readily.
Conclusion: Which Metal is “Stronger”?
The determination of which metal is “stronger” depends on the type of strength being measured. Pure gold is the winner in chemical strength, exhibiting resistance to corrosion and tarnish. Pure silver is negligibly harder than pure gold, giving it a slight advantage in physical strength when comparing the unalloyed metals.
In real-world applications, both metals rely on alloying to become durable. Alloyed gold, such as 14K, is physically much harder than fine silver, while sterling silver balances affordability and durability. Ultimately, the strength of the final material is determined more by the type and proportion of the base metals added to the alloy than by the precious metal itself.