Which term is a seventeenth-century designation for a diamond octahedron or other crystal shape on which the natural faces are apparent?

Which term is a seventeenth-century designation for a diamond octahedron or other crystal shape on which the natural faces are apparent?

• A. Point naif
• B. Pinpoint
• C. Pit
• D. Plot

Answer: (A)

The main idea here is historical terminology for a diamond’s natural crystal habit—the appearance of its original, uncut faces. The seventeenth-century designation for a diamond octahedron or other crystal shape with the natural faces still visible is called point naif. This term comes from French and literally conveys that the stone shows its naïve, or natural, crystal points rather than being fully cut into a gem. It specifically describes the unaltered crystal form, which is why it fits best for describing a diamond where the natural faces are apparent. The other terms don’t fit this concept: pinpoint and plot relate to tiny inclusions or features not about the crystal’s natural exterior, and pit refers to a flaw or cavity, not to the normal crystal shape showing its faces.

The main idea here is historical terminology for a diamond’s natural crystal habit—the appearance of its original, uncut faces. The seventeenth-century designation for a diamond octahedron or other crystal shape with the natural faces still visible is called point naif. This term comes from French and literally conveys that the stone shows its naïve, or natural, crystal points rather than being fully cut into a gem. It specifically describes the unaltered crystal form, which is why it fits best for describing a diamond where the natural faces are apparent.

The other terms don’t fit this concept: pinpoint and plot relate to tiny inclusions or features not about the crystal’s natural exterior, and pit refers to a flaw or cavity, not to the normal crystal shape showing its faces.