It's not a crystal, it's a portal.
I learned this while staring into Anomalous Object P-2145-T's ever-shifting facets. Yes, I had permission to study it. The truth is, my mind just drifted and I began staring. It was fascinating, the way its form changed continually, the way those little flakes of blue and red and purple scintillated just below the opaque white surface.
I was being drawn in, deeper, deeper, until I was no longer sitting in Anomalous Storage Room 34-B. I was… somewhere. Everywhere and nowhere. As if in a dream, I saw a scene before me and a thing that was supposed to be me, yet couldn't be me.
The world was bathed in red light, like a photograph darkroom. A vast looming blackness lurked behind the light, threatening to swallow it and return the world to the abyss from which it had spawned. The scene was framed with stark mountains, their faces like bleeding toenails in the light. They were bare save for various stones that sprouted haphazardly from them, as though growing in the rock face.
Yet for all that unfathomable immensity, the space upon which I looked was claustrophobic. The mountains nearest me were lower than those surrounding them, and hollow in the center. From them emerged enormous black silhouettes, like rounded tubes whose true natures I could not comprehend. They rocked slowly back and forth in the still air. Again and again, an enormous filament would emerge from the top of one, a ghastly thing as long as the creature's body, wreathed in swirling tendrils. Down it would snap, into the ruddy soil of that barren world, and then up again, retracting into the mouth that had spawned it.
Out, down, retract! Snap, snap, snap!
I was unable to do anything but watch them continue this behavior. I realized their targets were hundreds upon thousands of tiny black shapes that scuttled about the hills, oblivious to the sessile predators that towered over the landscape. The filaments speared the dots by the dozens and drew them back into the gaping maws.
I felt a shudder run through me, and I did not know why.
From the sky came a flash of light, and a tiny fireball rocketed to the earth. Then another appeared, and another, and soon there were dozens, streaking willy-nilly to impact with the red hills. Sometimes they left craters. Sometimes they were swallowed by the loose soil. Sometimes they annihilated the stone tumors growing from the mountainsides. Everywhere they landed, they flashed again and again, and I realized there must not have been an atmosphere, for I could hear no explosions, nor had I heard anything since finding myself in that alien landscape. With each explosion, hundreds of miniscule pinpricks of light were released, and the mountains were pockmarked with a shower of debris. Entire cosmoses of light were born and extinguished in moments. It was beautiful.
One of the exploding meteorites drew close to one of the titanic monarchs of the red valley and the tendril lashed out. It was met with an explosion and withdrew. Just as quickly as they had begun, the flashes began to die out. The final one attracted once more the attention of one of the creatures, that had not learned its lesson previously about airborne meals. This catch was successful, the tendril curling around the light and drawing it into the mouth. The top of the creature lit with an explosion, and a plume of dust curled out of the top.
Then the third feeder, the one that towered above its massive brethren, launched its tendril at me, catching me fast and drawing me inward.
In that instant, a thought came unbidden to my mind. The universe, it is theorized, began with an explosion, just a tiny speck of all-matter that burst and became all that we know and can conceive of. It expanded and expanded. Some say it will expand infinitely; some say that one day, it will simply stop, and everything will cease to be. Others claim that eventually a limit will be reached, after which the expansion will reverse. Further theories propound that the cycle will begin anew thereafter, creating a new universe and cycling indefinitely.
As the thing-that-could-not-be-me was dragged helplessly into the mouth of the thing-that-could-not-be, I knew what I would see. There, beyond the toothless maw, down the stygian esophagus to the incomprehensible depths of that being's stomach, lay a panoply of lights, uncountable by the human mind.
This creature, this mammoth tunicate whose existence was nothing more than an endless cycle of feed and feed again, had gotten lucky. It had plucked a star from the sky and taken it into itself fast enough to escape detonation, and now held within itself an expanding collection of stars, and I was being hurtled right into their center.
I know where these anomalous objects come from. I know why the Big Bang happened. I know that there will never be a Big Crunch.
For within that being's stomach, we all exist. We expand and expand, and eventually our existence will be ripped apart. There will be no repeating cycle. In our future, there lies only digestion.

Researcher Mayhew was granted a leave of absence for psychological evaluation on ██/██/████. Attempts to corroborate his statement about Anomalous Object P-2145-T have so far provided no results. However, reclassification as an SCP object is currently under consideration should testing prove productive.