Mica is derived from mineral sources. It is used for colour, so you can tell your bars apart. Wouldn't life be boring if it was all one colour! Mica is a mineral that is mined from rock and therefore totally safe for the planet. Mica is also safe for humans and animals. Mica has fallen under controversy recently with a murky supply chain that contains child labour and very unsafe working conditions. Whilst we do not buy our mica from sources that use Indian micas (where children are used in mines), we are actively looking for another colourant to remove any doubt. We are currently experimenting with synthetic mica (called fluorphlogopite) which is promising. It's a lab made synthetic ingredient which can produce brighter colours, is pure, natural and of course, biodegradable.