The note of Onyx, being an abstract and conceptual accord rather than a literal botanical extract, manifests as a profound mineralic depth. It is typically a cool, smooth, and stony presence, evoking the tactile sensation of polished, dark rock. The aroma is often characterized by a subtle, damp earthiness, reminiscent of petrichor clinging to ancient stone after a sudden rain, coupled with a faint, almost metallic coolness that speaks of subterranean chambers and quiet strength. There's an absence of sweetness or overt warmth; instead, it offers a stark, clean, yet grounding character. Its intensity is generally subdued, existing as a foundational element rather than a booming top note, preferring to anchor and provide texture. Projection is typically intimate, radiating a quiet authority. Longevity is excellent, as it resides firmly in the base, evolving slowly to reveal its inherent nuances over many hours, often becoming more earthy and profound as other notes recede.