Question

Use the diagnostic properties of beryl (e.g., hardness, refractive index, SG, habit, cleavage, fluorescence) to identify it.

Answer 1

Beryl can be identified based on its hardness, refractive index, specific gravity, habit, cleavage, and fluorescence properties.

Step-by-step explanation:

Beryl can be identified using various diagnostic properties:

1. Hardness: Beryl has a hardness of 7.5-8 on the Mohs scale, meaning it can scratch glass.
2. Refractive index: Beryl has a refractive index of 1.57-1.60, which determines how light is bent as it passes through the mineral.
3. Specific gravity (SG): Beryl has a SG of 2.63-2.80, indicating its density compared to water.
4. Habit: Beryl commonly occurs as prismatic crystals, but can also be found in granular or massive forms.
5. Cleavage: Beryl has poor to indistinct cleavage, meaning it does not break along smooth and flat planes.
6. Fluorescence: Beryl does not typically exhibit fluorescence under ultraviolet light.