The "black" sand (arena azul) comes from the mountains. It contains iron, and is attracted by magnets. This sand is small and in fact deep dark blue. Many beaches in Mexico are named "Playa Azul" (Blue Beach). That is not for the blue water or blue skies, it is for this blue sand. As this sand is usually covered by normal sand, you may not always see it. But when you are on a beach named this way, just dig 10 centimetres or so. Walking here bare foot mid day on dry sand may be difficult, but the blue sand gets more hot as the other. Watch your children, sometimes they get trapped half way in the direction to the see, or back, realising that back or forth is not a solution.
Lila Downs, from Oaxaca, sings a traditional song about black people in Mexico.
Tiny blue sand
The words in this song allude to the prejudices that face the black coastal people of Mexico. Faced with questions that would reduce the singer to belonging to an ethnic group she answers that she would just rather be a butterfly.