The top 3 highest grade resource deposits in Australia are...

The top 3 highest grade resource deposits in Australia are Greenbushes (1.5%), Mt Holland (1.53%) and BP33 (1.53%).
What deposit are you thinking exists in Australia that is higher than Core's BP33 deposit which would mean BP33 is not the best equal in Australia?

Grade isn't everything, but it indicates the potential for low-medium cost if you mine and process efficiently. Core would appear to be putting in place new arrangements around mining and processing that will put them in that low-medium cost space.

This table was produced by Pilbara and appeared in their September 2023 presentation pack. The projects below #20 had a maximum grade of 1.4% and that was a Canadian project. Across 47 project PLS table is consistent with this comment. Greenbushes has announced a resource upgrade to 447Mt which has dislodged PLS as the largest in Australia. The highest noted Australian project grade on that table is 1.53% (Mt Holland).


Core's recently released Mineral Resource Estimate: BP33 = 1.53%


References to both 186Mt and 189Mt @ 1.53% exist for Mt Holland. The 186Mt figure below is from the April 2022 Technical Report Summary on the Mt Holland Lithium Project.


Greenbushes:
Greenbushes has been expanding the size of the resource by pulling in average grade material. The IGO Dec 2020 report had Greenbushes at 178.5Mt @ 2.0% but the much larger average grade now being reported by Greenbushes are 1.5%. If the maximum LCE round up position is assumed the average grade is 1.49% so Greenbushes isn't sitting at a higher grade rounded down. 6.649Mt LCE would still be 6.6Mt. 6.649/447 = 1.487%.