Question

The use of diamond as a gem depends on its (1) hardness (2) high refractive index (3) purest form of carbon (4) chemical inertness

Short answer

(1) hardness and (2) high refractive index

Step-by-step solution

Understand the Question

Determine which properties of a diamond make it suitable for use as a gem.

Consider Hardness

Diamonds are known for being the hardest natural material, scoring a 10 on the Mohs scale of mineral hardness. This makes them very durable and resistant to scratches, an important property for gemstones.

Evaluate Refractive Index

Diamonds have a very high refractive index, which means they can bend light to a significant degree, creating a sparkling effect that is highly desirable in gems.

Assess Chemical Composition

While diamonds are composed of the purest form of carbon, this alone does not directly affect its use as a gemstone.

Examine Chemical Inertness

Diamonds are chemically inert, meaning they do not react easily with other chemicals. This property contributes to their durability but is not the primary reason for their use as gemstones.

Identify Key Properties

The hardness and high refractive index are the key properties that make diamonds suitable for use as gems. These properties ensure durability and the ability to reflect light brilliantly.

Formulate the Answer

Based on the evaluation, the primary reasons for using diamond as a gem are its hardness and high refractive index.

Key concepts

hardness of diamond

Diamonds are celebrated for their exceptional hardness. With a rating of 10 on the Mohs scale of mineral hardness, they are the hardest natural material known. This characteristic makes them incredibly durable and resistant to scratches. This means a diamond can retain its polish and smooth surface over many years, making it a perfect choice for jewelry, which is often worn daily. The hardness of diamonds not only preserves their beauty but also protects them from damage caused by everyday wear and tear.
Furthermore, their superlative hardness allows them to maintain sharp edges and facets. This is why they can be cut into an array of intricate shapes preferred in fine jewelry. It also ensures that other materials, except another diamond, cannot scratch or damage them, which is a wonderful trait for an enduring gemstone.

refractive index

Another standout property of diamonds is their high refractive index. The refractive index is a measure of how much a substance can bend light. Diamonds have a refractive index of about 2.42, which is quite high. This high refractive index implies that diamonds can bend and slow down light to a great extent, resulting in brilliant sparkle and dispersion of light into various colors.
When light enters a diamond, it bends at different angles, creating the signature diamond sparkle and fire that make gems so appealing. This property is crucial for gemstones as it significantly enhances their visual appeal, making diamonds one of the most sought-after materials for fine jewelry.
Thanks to this high refractive index, when expertly cut and polished, diamonds exhibit remarkable brightness and a play of colors that captures and holds attention.

properties of carbon

Diamonds are composed of carbon in its purest form. Carbon atoms in diamonds are arranged in a crystal lattice, which bestows them with unique properties. This pure form of carbon and the specific arrangement of atoms make them distinct from other carbon forms like graphite.
While the diamond's carbon content alone doesn't contribute directly to its gem qualities, it is significant for understanding the material. The carbon arrangement contributes to the hardness and the transparent quality of diamonds, which are essential for its sparkle and clarity.
Additionally, this pure carbon lattice is among the key contributors to diamond being the hardest material. It plays a vital role in the gem's structural rigidity and its unparalleled brilliance.

chemical inertness

Diamonds exhibit chemical inertness, meaning they do not react easily with other chemicals. In practical terms, this means that diamonds do not tarnish or corrode over time, a valuable property for jewelry items that are meant to last for generations.
The chemical stability of diamonds ensures that they maintain their appearance and structure even when exposed to various environmental conditions or substances like oils, perfumes, and cleaning agents.
Although chemical inertness is beneficial, it is not the primary reason diamonds are used as gemstones. However, this property contributes to their longevity, keeping them beautiful and intact without the need for highly specialized maintenance.
Their resistance to reacting with chemicals makes them ideal for daily wear as they face minimal risk from exposure to common household and industrial substances.