Where does come from?
The shamrock emoji, as it is officially called, was approved under Unicode 4.1 in 2005 and Emoji 1.0 in 2015. Everyone loves the Irish on St. Patrick's Day, so, for their sake, don't confuse the emoji why the four-leaf clover emoji, which has one more leaf than a shamrock.
Now for a bit of history:
Legend has it that, in the 5th century, St. Patrick used the three-leafed shamrock to explain the Christian concept of the trinity (God the father, son, and Holy Spirit, all in one) on his mission in Ireland, where the plant plentifully grows. By the 17th century, the story inspired the use of the shamrock as an emblem for St. Patrick, and, because the saint became so closely identified with the country, a symbol for Ireland as a whole.
Naturally, texters and tweeters have reduced that rich, complex history to a single emoji, calling it the St. Patrick's Day emoji.
Who uses ?
In text messages and social media, the St. Patrick's Day emoji is used to observe the holiday on or around March 17th. Expect it to be paired with the four-leaf clover emoji, the rainbow emoji, the Irish flag emoji, and—because Americans use the holiday as an excuse for a booze-fest—the beer mug emoji.
— Katherine McNamara (@Kat_McNamara) March 17, 2018
Given its symbolic associations with Irish people and culture, many people in and outside Ireland use the St. Patrick's Day emoji when talking about or taking pride in Irish life and culture.
— Jen the Wren 😉 (@Jenzzer) May 5, 2018
The emoji is very commonly used to rep the Irish-styled NBA team, the Boston Celtics, or Notre Dame College's Fight Irish teams as well.
— NBA TV (@NBATV) May 5, 2018
sooo pumped for st patty’s ☘️🍻💃
@matt_grajeda, March, 2018
Get loud!!! Thanks for your support! Go Irish! ☘️🏀👏🏽
@ndwbb, December, 2016
Ugh I can't wait to see Hanny tomorrow to reunite and plan our Irish vacation 😍☘️👯♀️🇮🇪
@jaycol19, December, 2016