Is grabbing jewelry possible?

As part of the A Chance Arrangement quest, I accidentally picked the jewelry box of Madesi (thinking his ring would be in there).

When I attempted to grab some jewelry from the display case and move it (so that I could be hidden when I stole it), I noticed that I could not pick the jewelry up from the display case. Instead, it seemed like the only interaction I could have was stealing it then and there.

Is it possible to grab jewelry, and if so, was it just a glitch preventing me from doing so?

As an aside, I'm playing on Xbox 360, have grabbed and stolen items in this way before, and have found no mention of being prevented from picking up jewelry on the grabbing wiki page.

Solution 1:

TL;DR

The physics which allow objects to be grabbed has been disabled on these items to prevent annoying bugs which often occur with display cases. Other jewellery found on the ground, counters and other surfaces should be fully interactive.

Explanation

In Skyrim all objects that can be added to the players inventory are "physics-enabled" which is the feature that allows them to move when bumped into, fall due to gravity and, yes, be grabbed by the player. Objects (or, rather, their in-game instances - or references) can be set to defer "Havok Settling" which means you can place an object anywhere and it won't react to physics until it comes into contact with another physics object (arrow, spell or even the player or an NPC).

An object in the Creation Engine is any world item, such as a door, barrel or sword. There exists one object in the engine for each item however each time an item is placed into the world a new "reference" is created. For example, there may be only one Glass Sword object in the game, but there could be any number of individual references (one for each physical Glass Sword in the game), plus new references generated by levelled lists.

If you cannot interact with the object through grabbing then I would say it's physics has been disabled by attaching the script defaultDisableHavokOnLoad to the object reference. According to the Creation Kit Wiki (emphasis mine):

[The script] is intended to make physics-enabled objects behave as if they were static.

This means that when the world loads (the Riften cell, in this case) the physics that would usually be applied to the jewellery in question will have been skipped, so it cannot be grabbed, fall to the ground or be affected by Unrelenting Force.

But, of course, the big question is Why? The usual reason for this is that the Havok Physics Engine (at least the iteration found within the Creation Engine) is poor at handling enclosed object collision. A typical bug is that a small Havok object is placed within an enclosed container such as a display case or bucket and the Havok Engine creates a rebound effect between the walls of the container. I can't find an online example of this exact case but this video shows the Havok Engine exhibiting the same behaviour on a Havok object between walls and the player.

By setting the object as static the bug is avoided, which was clearly seen as a more efficient alternative to fixing the engines' behaviour!