Faucet and facet are easily confused words.
The spell-check application of most word processing software programs would not catch a slip-up of these two words. Spell-check is looking for words that aren’t in its dictionary, and words that resemble words in its dictionary but are possibly spelled wrong. Spell-check isn’t perfect. It doesn’t know and can’t guess what word you wanted or what word you meant, it can only judge the words on the page. If you used words that are all spelled correctly, it gives you a pass anyway.
Autocorrect suggests words that start with the same letters. It’s suggesting what word you may want to save time, but quite often, its suggestions are pretty off base. They don’t help you out, but they do make you laugh.
Faucet is a noun. A faucet is a device that controls the flow of water or another liquid. Sinks and baths are probably the most well-known locations for a faucet.
Facet is a noun. A facet is a flat plane surface cut into a gem. The more facets that are cut into a gem, the more light it catches, causing the gem to sparkle and show its rich color. A set of facets and the general shape a stone is called a “cut.” Square, marquise, round, and princess are just a handful of the many cuts available for gems, see the link for more.
The following story uses both words correctly:
Faust was delighted with his latest discovery from the gem mines. After washing all the dirt and grime off at the faucet, he compared it to his gem book photos. Sure enough, it was a rare yellow diamond. Faust thought the marquise cut, with 58 facets, was the best way to showcase its beauty.