Identify the material that is NOT a high-alumina refractory raw mineral among the following options.

Introduction / Context:High-alumina refractories are derived from alumina-rich minerals such as the Al2SiO5 polymorphs and certain hydrates/oxides. Recognizing which listed material is not alumina-based helps avoid misclassification.

Given Data / Assumptions:

• Kyanite, sillimanite, and andalusite are Al2SiO5 polymorphs.
• Diaspore is an alumina hydroxide mineral (AlO(OH)).
• Periclase is MgO (magnesia).

Concept / Approach:All listed except periclase are alumina-bearing minerals used in high-alumina refractory production. Periclase is a magnesia mineral used for basic refractories, not high-alumina ones.

Step-by-Step Solution:Group Al2O3-rich minerals (kyanite, sillimanite, andalusite, diaspore).Identify periclase as MgO (basic).Select periclase as the non–high-alumina material.

Verification / Alternative check:Mineralogy references confirm compositions and refractory uses for each mineral listed.

Why Other Options Are Wrong:Kyanite/Sillimanite/Andalusite/Diaspore all supply alumina for high-alumina refractories.

Common Pitfalls:Confusing “basic” refractories (MgO-based) with “high-alumina” just because both handle high temperatures.

Final Answer:Periclase