The specific operating steps for testing crystal blocks are as follows:
Pretreatment: Clean the surface and remove impurities.
Visual Inspection: Observe characteristics such as color, transparency, and cracks.
Hardness Testing: Use a Mohs hardness scale (e.g., crystal hardness is 7).
Refractive Index Testing: Use a refractometer (crystal refractive index is approximately 1.544-1.553).
Density Measurement: Measure using the water displacement method (crystal density is approximately 2.65 g/cm³).
Polarizing Microscope Verification: Check for birefringence (crystal is an anisotropic material).
Supplementary explanations for the specific operating steps for testing crystal blocks are as follows:
First, ensure the sample is dry and clean. Use a 10x magnifying glass to observe internal inclusions (natural crystals commonly contain gas-liquid inclusions). Density testing requires an electronic balance (accuracy 0.001g) combined with the water displacement method. The calculation formula is: Density = Mass / (Volume of displaced water × Density of water). Refractive index testing requires reading the value in the refractometer contact solution (bromonaphthalene). The birefringence difference of crystal is 0.009. For quantitative analysis, it is recommended to use X-ray fluorescence spectrometry (XRF) to detect elemental content. For example, SiO₂ purity > 99% indicates high-quality crystal.
