The noun clay (type of soil material or its analogs) can also be used as a noun adjunct to mean of, about, or consisting of clay (e.g. clay sculpture). Adjectives that refer to being clay-like are rarely used, but are clayey or clayish.
clayish
Leather-hard (adjective) refers to a specific stage during the drying of a pot or other clay object. At this stage, the clay is still visibly damp (usually a darkish gray) but has dried enough to be able to be handled without deformation. The clay is able to be gouged or incised without breaking, but will not receive impressions.
An adjective describes a noun, whereas an adverb describes a verb. Ex of an adjective: Josephine is amazing with clay. In this sentence, amazing is describing a proper noun, Josephine. Ex of an adverb: Harvey runs quickly. In this sentence, quickly is describing how Harvey RUNS, which is a verb. Also: most adverbs end in -ly, so this is usually a clue on how to distinguish them.
Do you mean 'earthen'? Earthen is an adjective (a word used to describe a noun), not a noun (a naming word), so you can't say 'an earthen', you have to say 'an earthen something or other'. Earthen means that it is made out earth, in other words, that it is made from clay.
clay and life
Cassius Clay was actually Henry Clay's Nephew
Firing clay is when a clay is fired in a kiln, this is to make the clay stay strong.
Miry Clay is known as sticky clay.
clay molding is a art of molding a clay
a clay slab is a slab made of clay
A clay sheep is a sheep made out of clay
Clay is made of clay ...