The mica adds glitter to powders, mascara and lipsticks of top global brands although a complex supply chain makes pinning down the exact origin almost impossible, say activists....The families of the children who collect the mica often sell it to small traders who in turn sell it to big suppliers...In 2009, German pharma giant Merck was accused of using mica mined by children and supplying it to brands such as L'Oreal and Revlon...Merck has since implemented several measures to make sure that "all mica used for the manufacture of our pigments comes from child labour free sources," the company said in a statement....Activists however say remote areas make monitoring impossible and there is no way to guarantee the mica is child-labour free...Merck, our main supplier in India, only sources mica from legal gated mines and has submitted proof that its entire supply chain is secured," a spokeswoman for L'Oreal said in an email to AFP...Cosmetic giants such as Estee Lauder and Chanel have recently joined a scheme to help fund the education of children going back to schools.