Nice article on the origins of carnelian beads at two Sudan sites:

Six carnelian beads derive from the 9th -14th cen-tury layers of Banganarti (18°10’05.9"N 30°46’21.0"E), a Christian pilgrim site active during the Makuria Kingdom

and 18 beads and a two ake fragments dating to between the 15th–18th centuries come from excavations at Old Dongola (18°13’23.5"N 30°44’38.0"E), a capital of the Kingdom of Dongola

https://www.researchgate.net/publication/391569254_Tracing_the_origins_of_Carnelian_ornaments_in_Northeast_Africa_morphological_technological_and_chemical_compositional_analyses_of_beads_from_medieval_and_post-medieval_upper_Nubia_Sudan