What is an aluminum lake? Does it contain aluminum?
The term "lake" is used in food science to describe colour additives usually used in food and cosmetics. The US Food and Drug Administration describes the use of "lakes" as follows:
The name of a lake is formed from the name of the color additive combined with the name of the basic radical and the word "Lake". For example, the name of the lake prepared by extending the aluminum salt of FD&C Blue No. 1 upon alumina would be FD&C Blue No. 1 - Aluminum Lake.
If a lake is prepared by extending an FD&C color additive on a substratum other than alumina, the symbol "FD&C" will be replaced by "D&C".
For example, the name of the lake prepared by extending the aluminum salt of FD&C Blue No. 1 upon a substratum other than alumina would be D&C Blue No. 1- Aluminum Lake.
Aluminum Lake is a colour additive, typically blue. It is the blue in pill coatings and many other foods and drugs and in particular blue eye make-up products. Judging from more information listed at the FD&C site, you can make an aluminum lake of other colours as well, e.g. yellow. It also seems to involve combining Alumina (which is aluminum oxide, Al2O3, a naturally occurring mineral called corundum) a clear crystal or white powder, with a dye to make the lake. The alumina apparently acts as a vehicle or carrier for the dye.
Aluminum lake, therefore, is not the same as elemental aluminum.