Crystals

It was an unusual crystal to say the least. Not necessarily in composition, that was the confusing part. None of the chemicals were particularly exotic, nor did they have any unique properties in themselves. What was out of the ordinary was how long it took to grow the crystal. Even under ideal conditions, getting any appreciable amount of it would take literally hundreds of years.

Given that rather large timesink, the gate-keeping of the knowledge of how it was created was almost non-existent. Even once it's properties were known, they didn't seem to be of much practical use, as they were more or less fixed to that area – at least in a relative sense.

At it's most basic, all it seemed to do was have an odd effect on the quantum foam in a particular area. The addition shear effect it had created particle/anti-particle pairs more frequently and of greater magnitude than would normally be present.

What took a while to figure out was that the crystal was also growing into the past. Not quite as a physical object, but as far as the measurable effects went, they were present before a crystal was even conceived. That may seem like a paradox, but given that the process would only work it certain locations, it became a mute point.