from The Century Dictionary and Cyclopedia
- n. In petrography, a term proposed by Becker for andesitic lavas of light color which are porous in texture and consequently rough or harsh to the touch. The asperites are contrasted with the darker, denser andesites of basaltic habit. They are more commonly called trachytic andesites.
Sorry, no etymologies found.
But this is not the only ludicrous mistake that has arisen on the subject, since "swan-upping," or the taking up of swans, performed annually by the swan companies, with the Lord Mayor at their head, for the purpose of marking them, has been changed, by an unlucky asperite, into swan-_hopping_, which is perfectly unintelligible.