Some unusual words made this one a little harder for me than some recently from Quixote.
Solving time, 21 mins
Notes on some clues below, happy to explain others if asked.
* = anagram
ACROSS
12 OLD SA RUM (sold a)*
18 EL (OP) EMENTS Elements = bread and wine (from Christian service).
19 (g) O SLO (w) Extreme members = outside letters
DOWN
5 SPHALERITE (earth piles)*
8 SEPTUAGESIMA (I put a message)* 3rd Sunday before Lent – the day the puzzle appeared. Definition = today
17 HEN E QU(e)EN