Smoldering Spark Ruby

The progressive participle of smolder, to burn slowly without flame. Used as a color word since the late nineteenth century for the deep reds and oranges of barely-flame coal — the warm saturated darks where the heat is internal rather than emitted. Sits in the bold-and-warm corner, slightly less luminous than burning and slightly less calm than rich.

Old English spearca, small-ember. As a color modifier, spark implies a small-bright-and-flying-ember quality, the visual register of blacksmith-anvil-and-bonfire-spark hand-small-bright-and-flying-ember blacksmith-anvil-and-bonfire-and-flint-strike sparked-and-small-bright-and-flying surfaces under blacksmith-anvil-and-bonfire-and-flint-strike orange-glow-and-iron-and-flint forge-and-hearth-light. Sits at the modifier-and-mood end of the grid, parallel to flash and flare in usage.

From the Latin ruber — simply, red. The gemstone is a chromium-tinged corundum, harder than anything in nature except diamond, and so saturated that a fine Burmese pigeon's blood ruby at auction outpaces a comparable diamond by weight. The color borrows the gem's confidence: a clear, glassy red without the brown of garnet or the blue of crimson.