system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Trek Into Darkness] What was the ring made up of that caused such a large explosion?

**For those who are unable to access the data archives due to lack of clearance, please watch out because this has some classified information (AKA Spoiler Warning).**


When the one guy sits down at his desk at the Starfleet Library in London, he sends the email, takes off the ring he's wearing and drops it into the water cup. Shortly after we see from security footage that it explodes...violently. 

My current task is to try to figure out what that ring was so we can prevent this substance from being smuggled into secure locations this way.

We are currently lost. We at first were thinking it was some sort of alkali metal, such as Cesium, or even Francium, but that would never create an explosion that large from a ring that small. Plus it would have reacted with any moisture on his skin and in the air.

We then thought it may be some miniaturized fusion bomb as it could have used the hydrogen in the water for fusion. If it was, why did none of the radiation detectors see this when he was screened?

It's evident that massive amounts of heat are being generated as the ring starts fizzing and the water almost immediately boils before the explosion.

Some sort of fusion device is our best guess, but we are still unable to understand how such a device was miniaturized and concealed, or even if it was some sort of fusion based device.
gpt
Probably something like anti-hydrogen atoms (or even molecules of anti-water) sealed in a stable protective structure such as a carbon fullerene. Dropping the ring in water started a multi-stage chemical reaction that dissolved this protective structure, causing a run-away anti-matter explosion. A fraction of a gram of anti-matter would have been necessary to produce the explosion, and there would have been no detectable radiation.