Corp Gem Drop Table
Corp should drop multiple types of uncut gems at once;
This Archive.org capture from April 2009 of TipIts bestiary shows Uncut Gem (5) as a drop - worth noting that later revisions added square brackets around certain drops, including uncut gems, to denote that you get it in one kill (“Item groups are shown like [this].”). (http://web.archive.org/web/20090401001527/http://www.tip.it:80/runescape/?rs2monster_id=1200)
This Framed video from 2011 shows him getting one uncut emerald and three uncut sapphires from one kill (1:02 https://youtu.be/c_buIB7-L2A?t=62)
This Woox(second channel) video from 2012 shows him getting two uncut sapphires and coins from one drop. (4:16 https://youtu.be/5VIWEbgNcnc?t=256)
This OSRS video uploaded in 2014 very briefly shows a player getting at least two uncut sapphires and an uncut emerald from a kill - it’s cut off by the top of the chat window so I can’t see the whole list of gem from the kill. (1:43 https://youtu.be/s67cT87pl4w?t=103)
Looking at the RS3 wiki, old Fandom OSRS wiki there is a separate uncut drops table that if you hit will do a number of rolls allowing you to get multiple gems. The Fandom wiki lists hitting the uncut table; “The overall odds of hitting the 'Uncuts Drop' is 1 in 42.66.” (https://oldschoolrunescape.fandom.com/wiki/Corporeal_Beast#.22Uncuts.22_drop) The current OSRS wiki also has the uncut gem table (including drops from the RDT if you hit it from the uncut gem table) it also lists hitting this table as 1 in 42.66 and claims that you get ten rolls on it, Mod Ash twitter confirms the 1 in 42.66 hit chance but I’ve been unable to find a source for the ten rolls.