There are TONS of good examples in nature that could be used as a basis for this concept, and combined with each other. The most difficult aspect is "translucent" but even that isn't too hard to come up with. With some minor "magic"(or another variation of handwavium you prefer), it's not much of a stretch to get to what you described.
First, for plants:
Diphylleia, or skeleton flower, is a white flower whose petals turn transparent when wet.
Lunaria annua is a plant that has translucent seed pods
And Haworthia plants come in many varieties, some of which are translucent, and most of which are in a very crystalline arrangement.
Bio-luminescent fungus might be an inspiration for "glittering" plants or plantlike things. (keep in mind that some Lichen are fungus+plants in a symbiotic relationship, if you add bio-luminescence to that, and scale it up, you have sprawling and glittering plants and wall surfaces.)
For "glittering", the first thing that comes to my mind is fireflies, but then there are a huge variety of sea creatures that are also bio-luminescent. On land, most bio-luminescence seems to be bugs and bug larva, but there are bio-luminescent land crabs as well, and earthworms, and more. As a bonus, most bugs crabs and snails also have hard shells or exoskeletons, adding to the appearance of rigid crystalline structure.
For "iridescent", many snakes have literally iridescent scales, which are already crystalline both in shape and texture. Also, some snakes (and many other reptiles) have their scales "ruffled up" which would add to the crystalline appearance, look up Atheris hispida as a good example of this ruffled up appearance.
For "translucent" animals, this is by far the hardest, but there is a precendent for it, even for animals that have a hard(-ish) structure. There are glass frogs, but frogs in general aren't known for having a crystalline external structure. Fish scales are decidedly more crystalline in appearance already, and there are glass fish as well. Crustaceans, such as crabs and lobsters have a hard and stiff surface, and there are glass shrimp (mini-lobster-like appearance, but clear) that have a similar hard shell, though decidedly softer than the shells of most other crustaceans.
One final bit of inspiration that came to my mind for this question is scorpions in UV light.
In summary, real life ... life ... has plenty to choose from if you're looking for something to base fantasy glowing+iridescent+translucent+hard shelled plants and animals. Take the parts of real life that are the best for your story needs, mix them in ways that real life hasn't done, and you should be able to come up with something real-ish, but not real enough to be really real. (really)