In rhyming slang, the word that actually rhymes is frequently dropped; in this case it is china plate/mate. See, for example, http://www.aldertons.com/.
A charade is a type of cryptic clue in which the answer is divided into parts, with each part being indicated in the clue by a definition. Thus in 10A the answer MATERIAL id divided into MATE and RIAL. The part definitions are often strung together, just as the parts are strung together to form the answer, but in this case there is included the indication that MATE ‘needs’ RIAL to form MATERIAL.
Dickey, or more commonly dicky, does not come up in this crossword, but as it means in poor condition or defective, it is often used to indicate an anagram. Sometimes the surface of the clue – that is, the meaning you would take it if you did not treat it as cryptic – suggests the childish name for a bird. Dicky-bird, incidentally, is rhyming slang for word.

I’m not sure about LAPIDARY=beautifully clear; Chambers gives polished. Am I missing something?

I agree with you about 6A – the parts are all there, but your organisation points up the wordplay more clearly, and offers at least a good surface. However, I do think Arachne’s version works, read as “(With) English student rejected, clumsy (is) embrace”.

Stella

Looking back over the blog, I only spot a couple of typos, which is about par for the course. Anyway, in 16D, what is a “definition definition” but a double definition? It’s just that I cannot claim that was quite what I intended to write (or, at least, I can, but you might feel a touch of scepticism). I understand what you mean about unfair/dishonest, but Chambers, for example, does define UNFAIR as:

inequitable, unjust; involving deception or fraud and leading to undue advantage over business rivals; not fair, ugly.

That would seem to make unfair business practices definitely dishonest.

I plumped for “brocades” at first, too, and annoyingly gave up on the NE corner. For some reason, I was unable to see the well-known dd in 7d, and I’m not familiar with the expression DES-RES – in fact, I find it quite obnoxious; it doesn’t sound in the least desirable IMO. I read 6ac wrongly, expecting to find ‘el’ reversed in the answer, rather than excluded

Maybe it’s Monday morning syndrome, or the fact that I have things to do today. It was an enjoyable puzzle, with a few smiles, as usual with the Spider Woman, my thanks to her.

Just one quibble – I wouldn’t quite equate UNFAIR and ‘dishonest’

Arachne’s Quiptic offerings are usually enjoyable, and this was no exception. Just got held up on a couple: I too was trying to make BROCADES work, and I struggled with CARESS. The latter is slightly flawed, I think, since there’s no real indicator that you have to remove the EL from CARELESS. Would ‘Clumsy English student rejected embrace’ have worked better?

I liked the nicely hidden SESAME and ADVERB today.