The note of 'Frost' is not a singular botanical essence, but rather a masterful olfactory illusion, an accord crafted to evoke the very sensation of biting cold and crystal clarity. It presents as an intensely sharp, piercing, and ethereal freshness, almost metallic in its initial thrust, like the first inhalation of frigid air on a winter's dawn. It possesses a luminous, sparkling quality, often described as aldehydic or ozonic, creating an impression of vast, open spaces and pristine purity. There's an underlying clean, almost sterile, mineralic hum, devoid of warmth or sweetness, yet profoundly invigorating. Its texture is like powdered ice – dry, fine, and exquisitely delicate. Projection is typically sharp and immediate, often sitting at the top or very upper heart of a composition, acting as a brilliant flash before dissolving into a more grounded structure. Longevity can vary; while its initial 'sparkle' might fade, a subtle, cool transparency can linger, imbuing the overall fragrance with an enduring sense of crispness and weightlessness. It is the scent of light refracted through ice crystals, a silent, breathtaking chill.