When sourcing Arabian perfume oils, the primary quality indicators are concentration, purity, and longevity. High-grade oils, often referred to as 'Attars,' should be alcohol-free and possess a viscous consistency. Look for suppliers who provide Gas Chromatography-Mass Spectrometry (GC-MS) reports to verify the chemical composition and ensure the absence of synthetic fillers or prohibited phthalates. The scent profile should exhibit complex layering, typically featuring base notes of Oud (Agarwood), Sandalwood, Amber, or Musk.