[short_answer] Diamond and graphite are both made of pure carbon, yet they have strikingly different physical…

Question

[short_answer] Diamond and graphite are both made of pure carbon, yet they have strikingly different physical properties such as hardness and appearance. Similarly, talc and quartz are both silicate minerals but differ greatly in hardness. Using these examples, explain what factor — beyond chemical composition — determines the physical properties of a mineral.

Accepted Answer

## Model Answer Beyond chemical composition, the **physical and chemical conditions under which a mineral forms** determine its physical properties. Diamond and graphite are both pure carbon, but form under vastly different temperature and pressure conditions, resulting in different crystal structures — making diamond the hardest natural substance and graphite very soft. Similarly, talc and quartz are both silicates but their contrasting formation conditions produce very different hardness. Thus, it is the **internal structure** (crystal form) shaped by formation conditions — not composition alone — that determines properties like hardness, lustre, colour, and density. *Source: Chapter 5 — What is a Mineral?* --- ## Explanation The key phrase examiners look for is **"physical and chemical conditions under which the material forms"** leading to a **definable internal structure** — directly from the passage. Mentioning both examples (diamond/graphite + talc/quartz) and linking condition…

Social Science (087) — AI-generated practice question