When Did The Sydney Mint Start Producing Silver

G'day,
the Sydney Mint, as a branch of The Royal Mint in London, started producing gold sovereigns and half-sovereigns in 1855. These had a unique reverse upto 1870:
"Sydney Mint" was spelled out in full; above the word "Australia" (first time that that word appeared on a coin, I believe);
From 1871, SM produced sovs and halves similar to the London types. The "S" mintmark was on the obverse of the YH, and on the reverse of the JH coins.
The first distinctly Australian coinage of 1910 was minted in England.
The first silver coins were not minted at Sydney until 1921.
Except on the 1921 shilling, the Sydney mint had no mintmark on its silver coins, and they are indistinguishable from Melbourne silver.
The 1921 shilling was a low-mintage coin, and is addutionally sought after by collectors because it is the only silver coin which can be said to have definitely been minted at Sydney.
Australian silver coins with an "S" mintmark were minted at San Francisco in the years 1942, '43, & '44.
Peter in Oz