Smoldering Frock 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 French froc, monk's-habit-or-loose-garment. As a color modifier, frock implies a monk's-habit-and-pinafore-and-day-frock quality, the visual register of Benedictine-monk's-frock-and-Edwardian-day-frock hand-monk's-habit-and-pinafore-and-day-frock Benedictine-monk's-frock-and-Edwardian-day-frock-and-pinafore frock-and-monk's-habit-and-pinafore surfaces under Benedictine-monk's-frock-and-Edwardian-day-frock-and-pinafore Cluny-Abbey-and-Edwardian-tea-room habit-and-day-dress-light. Sits at the modifier-and-textile end of the grid, parallel to gown and cope 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.