Out of curiosity are you talking about minkisi bundles? my favorite archaeology professor who is now retired specialises in that stuff. He talked a lot about how enslaved people kept practicing their african spiritual traditions hidden in plain sight. A minkisi bundle contained 'flash' which was white or shiny material (glass, crystal, white ceramics, etc) that represented water and called the spirit, a piece of iron or steel, and something belonging to the target person to instruct the spirit what to do. They could be used to curse people or to protect them depending on the intent of the person who put them there.

Naming my professor comes at the risk of doxing the university I go to, but this article is about what I'm talking about:

Matthews, Christopher N. (2011) "The Archaeology of Race and African American Resistance," African Diaspora Archaeology
Newsletter: Vol. 4 : Iss. 1 , Article 16.
Available at: https://scholarworks.umass.edu/adan/vol4/iss1/16

-- Janusz