True. But most of the mixtures sold as Anchor Cement are technically concrete as they are not pure cement - but a mixture of cement, sand (or gravel or other aggregates) and ‘special additives’, depending on the manufacturer and/or intended use.
You can clearly see aggregates in the pictures of the keychain in the original piece on http://sayyestohoboken.com/2013/12/diy-cement-faceted-key-chain.html
http://www.sakrete.com/uploads/downloads/Sakrete%20Anchor%20Cement%20Tech%20Data%206-101.pdf
