In materials science, which mineral form of carbon is commonly used as the starting material for producing artificial or synthetic diamonds?

Introduction / Context:
Artificial or synthetic diamonds are widely used in cutting tools, abrasives and high pressure research. This question asks you to recall which mineral is typically used as the carbon source when manufacturing synthetic diamonds, connecting basic geology with industrial applications.

Given Data / Assumptions:
• The product is an artificial diamond, which is crystalline carbon.
• We are looking for a mineral that can supply carbon atoms under high pressure and temperature conditions.
• Options include several non carbon minerals such as quartz, corundum and bauxite.

Concept / Approach:
Diamonds are a crystalline form of carbon. To make synthetic diamonds, manufacturers start with a carbon rich material and subject it to high pressure and high temperature in the presence of catalysts. Graphite is a natural mineral composed entirely of carbon atoms in layered structures. Under the right conditions, graphite can transform into diamond, which is denser and has a different arrangement of carbon atoms. In contrast, quartz is silicon dioxide, corundum is aluminium oxide, bauxite is an aluminium ore, and silica generally refers to silicon dioxide, none of which provide elemental carbon.

Step-by-Step Solution:
Step 1: Recall that diamond and graphite are both allotropes of carbon, meaning they are different structural forms of the same element. Step 2: Recognise that synthetic diamond production requires a carbon source that can be rearranged into the diamond structure. Step 3: Identify graphite as the only option among the choices that is made purely of carbon. Step 4: Note that quartz and silica are silicon dioxide, corundum is aluminium oxide, and bauxite is a mixture of aluminium bearing minerals, not carbon sources. Step 5: Conclude that graphite is the mineral used to produce artificial diamonds.

Verification / Alternative check:
Descriptions of high pressure high temperature and chemical vapour deposition methods for making synthetic diamonds frequently mention graphite powder or other carbon sources as the feed material. No industrial process uses quartz or bauxite as a direct carbon source, confirming that graphite is the expected answer.

Why Other Options Are Wrong:
Quartz: A mineral of silicon dioxide, SiO2, used in glass and electronics, not in diamond synthesis as a carbon source.
Corundum: Aluminium oxide, Al2O3, used in abrasives and gemstones such as ruby and sapphire, but it does not supply carbon.
Bauxite: A mixture of aluminium rich minerals, the principal ore of aluminium, and again not a carbon based material.
Silica: Another name for silicon dioxide, similar to quartz, lacking carbon needed for diamond formation.

Common Pitfalls:
Some students may focus only on hardness and recall that corundum is also a very hard mineral, leading them to pick it. However, the question is specifically about a mineral used to produce diamonds, not another hard substance. Always connect artificial diamonds to their basic chemistry as pure carbon and remember that graphite is the common carbon allotrope that transforms into diamond under extreme conditions.

Final Answer:
The mineral commonly used as the starting material to produce artificial diamonds is Graphite.