Final answer:
X-ray diffraction is not a physical property used in the field to identify minerals; instead, color, luster, and specific gravity are the commonly used physical properties.
Step-by-step explanation:
Among the options provided, X-ray diffraction is NOT a physical property commonly used in the field to identify minerals. X-ray diffraction is a laboratory-based technique that requires sophisticated equipment to analyze the crystalline structure of minerals. In contrast, properties such as color, luster, and specific gravity are physical properties that can be observed directly in the field without the need for complex instruments. Color is the most obvious property but it can be deceptive due to variations in a mineral's appearance. Luster describes how a mineral reflects light, categorizing it as metallic or non-metallic. Specific gravity is related to the density of the mineral and can be approximated in the field by the heft of the sample.