Pearl or parasite enters a bivalve mollusk and settles inside the shell. The mollusk, irritated by the intruder, forms a pearl sac of external mantle tissue cells and secretes the calcium carbonate and conchiolin to cover the irritant. This secretion process is repeated many times, thus producing a pearl. Natural pearls come in many shapes, with perfectly round ones being comparatively rare. Typically, the build-up of a natural pearl consists of a brown central zone formed by columnar calcium carbonate (usually calcite, sometimes columnar aragonite) and a yellowish to white outer zone consisting of nacre (tabular aragonite). In a pearl cross-section
The Pearl of Africa (film) The Pearl of Africa (film) The Pearl of Africa is a documentary film directed by Johnny von Wallstroem, it focus on the life of Cleopatra Kambugu, a Ugandan born woman who decide to live openly as a trans woman despite hostility towards same-sex relations in the country. The phrase Pearl of Africa is attributed to Winston Churchill who used it to describe Uganda's flora and fauna. In 2014, when the protagonist and her lover decide to settle down quietly, Uganda passed a homophobic law; later in the year, a Ugandan tabloid, "Red Pepper" outed Kambugu which eventually forced the lovers