When the DM tries to make it as obvious as possible

This just gave me the idea of an item that is secretly highly radioactive. Carrying it and being around it it would slowly give the character increasingly acute symptoms of radiation poisoning.The characters can't possibly understand what radiation poisoning is so they would think it is some sort of magical curse. However no magic users would be able figure out what it is and how to stop it.
I'm wondering how long it would take for the players themselves to figure out what it really is, or if they ever would.
- "You decipher the runes - they say 'Drop and Run'."
  
  The dungeon entrance is marked with a message in an ancient language called "English." It reads as follows:
  This place is a message... and part of a system of messages... pay attention to it!
  Sending this message was important to us. We considered ourselves to be a powerful culture.
  This place is not a place of honor... no highly esteemed deed is commemorated here... nothing valued is here.
  What is here was dangerous and repulsive to us. This message is a warning about danger.
  The danger is in a particular location... it increases towards a center... the center of danger is here... of a particular size and shape, and below us.
  The danger is still present, in your time, as it was in ours.
  The danger is to the body, and it can kill.
  The form of the danger is an emanation of energy.
  The danger is unleashed only if you substantially disturb this place physically. This place is best shunned and left uninhabited.
  $10 says the party decides to delve for treasure anyway.
  
  10 minutes to widespread organ failure is a bit short for the players to figure anything out.
  
  🫳🏃‍➡️
- The demon core.
  
  "Hey, I speak Infernal! ... what tastes like blue?"
- If they do figure it out you could be in for a very long debate about how far away something is inside a bag of holding.
  
  As far away as the center point of the Big Bang
- A modernist version of Spoony's favorite TTRPG, "Surprise! It's Call Of Cthulu."

There is an old movie called "Mom and Dad Save the World." It's pure entertainment.
The planet is full of idiots and one of their most dangerous weapons is the light grenade. Anyone who picks it up disappears in a bright flash. So, why would anyone ever pick up this well-known weapon? Because it says "Pick me up" on the side.
- Never in my life have I found someone else who knows about that movie. Scene in question
  
  I watched the crap out of it as a kid. I remember it being very weird.
  
  I've seen this! But I didn't recall that until I saw this scene. Must have been on cable in the early 90's? Good times.
  
  "Let's hope these guys are really stupid"
  
  The mushroom creature has stayed with me for more than 30 years.
  
  Oh hey, it's that pedophile from ferris bueller
  
  Oooohh nostalgia!
- Oh good, I was thinking of that exact thing, but I couldn't remember the name of the movie. I remember it being surprisingly funny.

"Alright guys, so, obviously it's cursed. But imagine how good it would be if we could sneak it into some bad guy's pocket. I pick up the gem."
- GM: "Uhh, allllriiiiight. Make a wisdom saving throw. DC: fuck you."
  
  Player: Somehow rolls Fuck You +1
  GM: ...
  GM: Uhhhh, I'm gonna need 15 minutes
  
  "Does a 40 save?"
  "Look me in the eyes, and tell me: should it?"

Holy shit check out that spear in the corner! I bet it's awesome, since all these people died protecting it.
The rust, scratches, and broken haft are probably just to disguise it.
- If my players said that from this image the spear would suddenly become a pretty sick magic item.
  It's also cursed though, like the one ring, to cause jealousy and greed
- My guy stumbles over the gemstone en route to the spear.

skeletons and filth everywhere EXCEPT the gem
- The sacred artifact of absolute cleanliness!
  
  Unfortunately, someone once said the phrase "human filth" within a 500 ft range of the artifact and it never forgot.

Those other skeletons were just quitters.

This looks like a job for my unseen servant (or phantasmal minion for people who play the Pathfinder Remaster)!

I hit it with my sword!

I bet that skull has some magic power!
- Argh. I can feel this one.
  My party often gravitates to the grossest random ad-hoc detail.
  "I'm pretty sure that dead animal carcass is magical. I stuff it in my bag."
  ... Much later ...
  "I dump the dead carcass on the Wizards desk and ask him to cast 'detect magic'".
  ...party proceeds to remind me (the DM) that they've carried a dead animal carcass in a backpack for half the campaign...

A new hand touches the beacon...
- No no, I don't touch the strange glowing gem, I will however lacrosse that bitch into my magic satchel and keep truckin and have it appraised later.

I approach the Obelisk,.
- I got that reference!

Totally, 100% for sure not related to all those skeletons on the floor.

Nope that's a trap. I think the DM mentioned something shiny in the flavor text an hour ago though. We should track that down.

Lol, Tomb of Horrors last resort wish gem.

oh come on, man. mage hand/unseen servant that shit into a bag of holding and forget about it for 3 years.

Not only am I going to pick it up, I'm gonna try and eat it