Strange. For me, being a German, smykke and smukke sound completely different and are clearly distinguishable. That obviously means that it takes some practice to hear the difference between these two sounds. So anyone who has a problem with this: Don't worry, keep on practising!
A jewel is a gemstone or may even refer to a semi-precious stone (opal, moonstone, topaz), but jewelry doesn't always have a gemstone in it. It can be just metal, or it can be a setting with something other than a gemstone, like feathers, glass, plastic, etc. A gemstone isn't jewelry unless it's in a setting and can be worn. Is that what you were asking?
jewel (plural jewels)
A precious or semi-precious stone; gem, gemstone.
A valuable object used for personal ornamentation, especially one made of precious metals and stones; a piece of jewellery.
So I think it should be accepted.
I know the literal translation is "A piece of jewelry", but many of my peers colloquially refer to ornamental wear of all varieties (matte as well as reflective) as a "Shiny". (Usage: "Ooh, you got a new shiny!") Would that fly as a translation? I don't want to report it as an error if it's too specific to my peers.
First reading your comment reminded me of this British kids' TV show: https://www.youtube.com/watch?v=0lgIwh9VE2M
But to actually answer your question, it's not something I've heard and I can't find any trace of "shiny" being used as a noun in any dictionaries other than on Wiktionary, where it's defined as "anything shiny; a trinket", which I wouldn't regard as the same as a piece of jewellery