Booming Rain Sapphire

Imitative-onomatopoeic origin — present-participle of boom, sharing root with Dutch bommen. As a color modifier, booming implies a saturated-and-loud-and-confident quality where the hue announces itself with full visual amplitude. Sits at the bold-and-resonant end of the grid, parallel to resounding and thunderous.

Old English regn, rain-or-shower. As a color modifier, rain implies a rain-shower-and-wet-and-Atlantic-front quality, the visual register of Atlantic-front-rain-and-monsoon-rain hand-rain-shower-and-wet-and-Atlantic-front Atlantic-front-rain-and-monsoon-rain-and-Lake-District-deluge rain-and-rain-shower-and-wet surfaces under Atlantic-front-rain-and-monsoon-rain-and-Lake-District-deluge Cumbrian-fells-and-Borrowdale-and-Snowdonia Atlantic-rain-light. Sits at the modifier-and-weather end of the grid, parallel to sleet and flurry in usage.

An iron-and-titanium-bearing corundum — the same mineral as ruby, hardness 9 on the Mohs scale, mined for two millennia from Sri Lanka, Burma, Madagascar, and the Cashmere mines of British India. The color refers to a fine Kashmir-cut sapphire: a saturated, slightly violet-shifted deep blue with the gem's signature internal velvet — a quality of light scattering in the stone that faceted glass cannot replicate. Cooler than cobalt, deeper than azure.