Quality evaluation depends on the clarity of the host quartz, the density and color of the rutile inclusions, and the precision of the cut. High-grade specimens should feature transparent crystal without cloudy 'milkiness.' The 'needles' (rutile) are most valuable when they appear in golden, copper, or silver hues and are arranged in desirable patterns like 'Star' or 'Cat's Eye' effects. Ensure the surface is free of cracks or pits that could compromise the stone's structural integrity during jewelry setting.