Question

The use of diamond as a gem depends on its: (a) Chemical inertness (b) Hardness (c) Purest form of carbon (d) High refractive index

Short answer

The use of diamond as a gem primarily depends on its high refractive index (d).

Step-by-step solution

Understand the Properties of Diamond

Diamonds are valued for several unique properties. These include chemical inertness, hardness, purity as a form of carbon, and a high refractive index. Analyze these properties to determine which is most relevant to its use as a gemstone.

Analyze Each Property

(a) Chemical Inertness: Diamonds do not react easily with chemicals, making them durable. (b) Hardness: Diamonds are the hardest known natural material, which makes them resistant to scratching. (c) Purest Form of Carbon: As a form of carbon, they exhibit high strength and transparency. (d) High Refractive Index: Diamonds have a high refractive index, which means they bend light distinctly, resulting in brilliance and sparkle.

Focus on Properties for Gem Use

When considering diamonds as gemstones, the appearance is critical. The brilliance and sparkle caused by the high refractive index are essential qualities that make diamonds desirable as gemstones.

Conclusion

Among the options, the high refractive index (d) is the primary factor for their use as gems, as it gives diamonds their characteristic sparkle and brilliance, making them highly attractive.

Key concepts

Chemical Inertness

Diamonds are chemically inert, meaning they exhibit a resistance to chemical reactions. This property is significant because it contributes to their durability and longevity, which are highly desired traits in gems. Given their inertness, diamonds do not tarnish, corrode, or alter when exposed to common substances, such as water or acids. This makes diamonds exceptionally durable, ensuring that their luster remains intact for years.
Furthermore, this resistance allows diamonds to maintain their appearance and value over time, making them excellent investments. Whether they are worn as jewelry or passed down through generations, their chemical stability ensures enduring beauty.

• Resistant to tarnishing and corrosion
• Maintains luster and appearance over time
• Does not react with common chemicals

Thus, the chemical inertness of diamonds not only contributes to their beauty but also secures their status as a reliable and lasting gemstone.

Hardness of Diamonds

Diamonds boast a supreme hardness that makes them the hardest known natural material on Earth. This characteristic is quantified by a ranking of 10 on the Mohs scale, a testament to their resilience and ability to withstand scratches from other substances.
The hardness of diamonds ensures their surfaces remain unscathed in daily wear, which is why they are preferred in jewelry that is worn frequently, like rings. On a practical level, this hardness allows diamonds to be used industrially in cutting, grinding, and drilling applications, showcasing their versatility.
In the context of gemstones, a diamond's hardness preserves intricate cuts and facets, maintaining its form and shine over time. This makes them particularly attractive for fine jewelry, where maintaining clarity and luster is essential.

• Ranked 10 on the Mohs scale
• Maintains shape and form
• Used in industrial applications due to strength

Hardness, therefore, is not just an integral aspect of a diamond’s structural integrity but also a key feature in its desirability as a striking and enduring gemstone.

High Refractive Index of Gems

One of the defining features of diamonds as gemstones is their high refractive index. This property explains why diamonds are renowned for their remarkable brightness and sparkle. The high refractive index allows diamonds to bend and disperse light efficiently, creating the beautiful play of colors known as "fire." This is the characteristic sparkle that captures the eye and makes diamonds so visually stunning.
When light enters a diamond, it travels slower within the gem, bending and exiting at various angles. This process disperses light into different colors, enhancing its visual appeal. The high refractive index is a critical factor for the brilliance diamonds are famous for, distinguishing them from other gemstones.

• Causes brilliant sparkle and fire
• Light dispersion creates a play of colors
• Key factor in the attractiveness of diamonds

As a result, the high refractive index is arguably the primary reason diamonds are considered the pinnacle of gemstone artistry and treasured worldwide for their luminous beauty.