stalactite work at English => English (The Britannica Concise) Of Explained:
Honeycomb-like Islamic architectural ornamentation formed by the intricate corbeling (see corbel) of squinches (see Byzantine architecture), brackets, and inverted pyramids in overlapping tiers. It appeared in the early 12th cent. throughout the Islamic world; a frequent use was to overlay the transitional zone between domes and their supports. It reached its highest development in the 14th-15th cent., when it became the usual decoration for door heads, niches, and the bracketing under cornices and minaret galleries. Rich examples are found in the Alhambra and other Moorish works in Spain.