Joules and jewels are easily confused words and homophones.
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.
Joules (pronounced “joolz”) is a plural form of the noun joule. A joule is a unit of measure, used to indicate work or energy expended.
Jewels (pronounced “ju+wools”) is a plural form of the noun jewel. A jewel is gemstone or pearl that’s set into metal or wire to be worn for decoration. Gems that have been set into rings, earrings, and necklaces are jewelry.
The following story uses both words correctly:
Little Jorge was scared when he dropped his mother’s jewels while playing with them. He feared they were glass and would break. Surprisingly, they bounced slightly off the floor. Watching them fall, collide, and fly again captivated him. He didn’t know the measurement was a joule, but he wondered what energy was involved in the jewels’ falls and rises, and how much energy each movement took.
SIDENOTE: Jules can also be a male’s name. It can also be a nickname for women named Juliet, Julie, or Julia.