Practical Mineralogy

Voorkant
H. Bailliere, 1843 - 192 pagina's
 

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Veelvoorkomende woorden en zinsdelen

Populaire passages

Pagina 193 - Scratches glass, though rather with difficulty, leaving its powder on it. Yields readily to the knife. 6. Scratches glass easily. Yields with difficulty to the knife. 7. Does not yield to the knife. Yields to the edge of a file, though with difficulty. 8. 9. 10. Harder than flint.
Pagina 193 - Chapman : 1. Yields easily to the nail. 2. Yields with difficulty to the nail, or merely receives an impression from it. Does not scratch a copper coin. 3. Scratches a copper coin; but is also scratched by it, being of about the same degree of hardness. 4. Not scratched by a copper coin ; does not scratch glass.

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