A flame-like vein or color variation in granite; also a flame-shaped architectural ornament.
In French quarry vocabulary, flamme can describe a vein or color variation in granite caused by differences within the stone. The same word is also used for a sculpted ornament or crowning element shaped like a tongue of flame.
Etymology
French flamme, 'flame.'
References
https://www.pierres-info.fr/glossaire/index.html