Unpolished
There would always be ponies who wished to impress or just plain upstage others.
This meant a reliable flow of orders for Rarity's services as a dressmaker. While this meant profit as well, it also meant she occasionally ran low on raw materials. Cloth could be easily ordered and arrive without further intervention, but cloth alone hardly suited the tastes of the top spenders at Carousel Boutique. They wanted special. They wanted shine.
Whether whole for accents, or crushed and tumbled for a brilliant, sequin-like appliqué, this meant gems. Rarity could opt to pay extortionate fees from wholesalers, or she could concede that Applejack was right about there being no substitute for honest labor, and get them herself.
Today had been a standard hunt, the pattern rote and very nearly boring at times: Rarity's eyes would close or gaze into the distance, her horn alight as it guided her to a spot where gemstones had risen steadily from below, and Spike would use his dexterous claws to excavate them. It was hardly a necessity that he assist, but when he was available he would never take no for an answer. It also spared Rarity the magical fatigue that came from extracting those gemstones on her own.
Now at the end of the day, he was following close behind, carrying their rather substantial haul. Even caked with loose dust, Spike found it all too tempting to make a quick snack of one of them, but his will was strong. Some years spent with Twilight and her friends had seen to that: When ancient evils and eldritch horrors visited on a worryingly regular basis, and with his own draconian nature a constant threat from within, Spike had become quite capable of withstanding temptation.
His thoughts began to stray as the expedition drew to a close, recounting how long it had been since the last time someone or something had tried taking over the world, or at least Ponyville. His rambling inner checklist came to a sudden end as he ran directly into Rarity's far softer one. He'd later count his blessings that both of them were far too distracted to realize just how awkward that had been.
The day had been normal enough, but Rarity now found herself questioning whether she hadn't been out in the sun too long, because she swore that neither she nor Spike had made the crater she almost stepped into. Even stranger, the depression in the ground was almost too smooth, like it had just caved in with no visible excavation. "Spike, darling?" she started, glancing sideways at the pit.
"Mmm?" he responded eloquently, shaking his head, still reeling from the impact as he rose to his feet.
"Did we dig here?"
He was finally able to look at the offending, relatively shallow hollow and scratched at his chin thoughtfully while going over his memories of the excursion so far. "I'm pretty sure we didn't." He hadn't been that distracted during the dig, just toward the end. He now scolded himself for having lost focus like that. After all, he owed it to Rarity to not let the diamond dogs approach unobserved again. The fact that he didn't recall making a stop here now put him on an even higher alert. It might very well be a sign that the dogs were about.
Rarity's pensive expression melted into a smile as her companion scanned the horizon with an intensity usually reserved for the royal guard. "Well, don't fret too much, dear. If they're still around, the brutes know better than to try to inconvenience us again. We've not seen them for months. Years, even!"
"Yeah, I guess you're right," he conceded, relaxing visibly and moving to pull the wagon around the dip in the soft ground. "Can't be too careful, though."
They made their way back to the Boutique to unload their cargo, disregarding what was surely a fluke of an occurrence.
A week later, Rarity was sorely wishing she'd brought Spike with her again. He'd have been brave for her, and she'd have been confident in return…but she was alone that day.
As soon as she got to her gem-diving grounds, scores of pits already marked the landscape like the surface of the moon. Half-coherent visuals from her time there, in the Nightmare's grip, mingled with very vivid recollections of the last run-in she'd had with the diamond dogs those scant few years ago. Neither were a realistic threat anymore, but rationality had abandoned her to her own devices. She began trembling on her hooves an instant before turning and bolting back toward home. Past concerned glances from the townsponies, she didn't stop running until she collapsed into a quivering heap on her porch.
Her eyes never closed until she had the strength to stumble inside and fall into restless sleep on her nearest fainting couch.
Be strong, Rarity, she told herself. You can do this. Only memories lurk here, and a memory cannot harm you.
It had been not a full week since the last time she'd dared to come out to the desolate woodlands outlying Ponyville. Fancy Pants meant well, but his casual suggestion to some of his peers that Rarity was the pony to go to for dresses that weren't obviously bought from a shop had preceded a wave of orders. It was made abundantly clear that she would have to replenish her gem stocks. She couldn't wait for Spike, either; he was stuck assisting Twilight today.
Once she crossed the threshold, however, the unease she felt dissipated a step at a time. The grounds were as smooth as they'd ever been, and a casual flicker of her magic told her that the constant activity below had worked enough gems near the surface that she'd never be able to bring them back in one trip, even if she'd had Spike with her. Today was going to be a good day, she could feel it!
With a smile and a determination that would see her through a day of work, she approached the faint tugging of the first deposit. This part would be grueling by any unicorn's standards, but she'd grown efficient at it. Once close enough, she spread her stance on the ground, located each and every gemstone in a small area, and latched onto them.
Unseen but felt, they started vibrating.
It had taken some time and practice to adapt the techniques Twilight Sparkle had used to create music on an array of tubular bells, and she'd never have gotten the idea to do so unless the town's resident former rock farmer had demonstrated on a separate occasion--using actual sugar and gumdrops, of course, which were promptly devoured after--how gems made their way to the surface in such farming grounds. It came down to smaller particles settling while larger ones rose, but the shifting lessened at the surface. Give things a little shake, though...
Her magic flared once, and the ground trembled in a dozen places before shards erupted with a spray of dust and dirt. The cloud settled, and she didn't even mind the fallout that darkened her pristine coat as she looked upon the fruits of her labor: Suspended in the air within her azure aura was a cluster of gems that, even unpolished, shone beautifully in the sun. These would do nicely, she thought, as she swept them into her ample saddlebags.
Now to do that trick another three or four dozen times.
The finding and build-up was easy, but each burst of magic took a substantial bit out of her. It began with a tingle in her horn, similar to the satisfying ache she'd get from her warm-ups before yoga. Soon it became a vague burn as she flexed her magical muscle again and again. As her cache filled, her reserves drained, and even before afternoon had properly begun she was exhausted. It was all planned for, though; a bath and a nap before Sweetie Belle got home from school would see her rejuvenated enough to take care of her little sister and begin working on her haul.
Oh, but that spot under her hooves just felt tempting! One more extraction, and she'd go home. Besides, her bags simply would not hold more beyond this. She focused on a tightly-clustered group, set her stance, began to vibrate the stones, and as soon as she felt them loosen, she pulled with the last of her energy.
She promptly fell back on her flank. The straps only barely kept most of her payload from spilling out of her saddlebags with the impact as she pulled at nothing. There was simply nothing left, which became apparent as the ground caved in a bit, leaving a depression before her that was all too familiar. She felt a surge of panic, but immediately realized something.
The gems had been teleported away. She would have felt the pull of a diamond dog's grubby paws at the gems she was essentially holding. Another unicorn had taken the gems, and it had to have been a rather powerful one to have overridden her magic without her even feeling it at first. Rarity scanned the horizon as she picked up the few spilled stones, and found what she was now looking for:
Her competition.
Rarity approached, walking around a line of similar indentations in the ground, immediately thinking there was something familiar about this other pony. From this distance she observed a violet aura holding the entire clump of soft earth, which fell away at a little shake--a dozen or so similar mounds of discarded dirt surrounded her--leaving its payload for the taking. As interesting as the new technique might have been any other time, her blood boiled at the sight. Those had been hers! Her eyes narrowed and she gave an annoyed, very un-ladylike snort as she picked up her pace, fully intent on giving this interloper a piece of her mind!
The mare with the powder-blue coat was unhurried as she trotted along, and even as exhausted as she was, Rarity soon drew near enough to clear her throat and be heard. "Ahem! Excuse me, darling," she started with an edge to her voice. Her choice of words and tone did not match, but perhaps over a mere misunderstanding, it wasn't the best idea to come out verbally swinging.
The other mare turned about, silver mane framing an all-too-familiar face. A conspicuously absent cape was easily imagined in place now that there was recognition. Rarity's eyes widened. "You!"
In hindsight, perhaps 'Oh, it's you!' would have been better, but the stage had now been set for this battle, and the egos ensured that both of the armies had no choice but to participate.
"Why, yes, me," declared the unicorn, setting the contested clump of gems down at her side. "And what do you want with the Great and Powerful Trixie, hmm? I'm quite busy working, as I'm sure you can see." Trixie's mind raced even while she spoke, reflexively aiming to put any aggressor on the defensive. This mare was familiar somehow, she was sure of it, but she only really committed one of the Ponyville residents to memory. Was this possibly one of her friends? Surely not; Twilight Sparkle was the Princess of Friendship, and would have friends who would make better first impressions than this!
"Oh, forgive me! Busy working, are you? Working to steal those right out of my hooves, it would seem," Rarity countered sharply.
So that's what the tingle she'd felt was? She hadn't paid much mind to the odd feeling as she'd teleported the gem-laden dirt to her for sifting, but another unicorn holding onto it would have accounted for it. "Well, Trixie might have apologized, if somepony deserved it," she replied with a flip of her mane. "As it is, I think I'll hold onto them as fair trade for this vicious and unwarranted attack on my character. Good day, whoever you are!" Trixie turned to leave, gathering up the gems.
"I. Am. Rarity," she growled, her decorum gone with the breeze that rustled the sparse trees and foliage about them. "A name you would do well to remember if you should have a notion to darken our fair town again."
She turned back at the insult, a cold smile on her lips. "Ah, yes, now Trixie remembers you. Ironic, don't you think?" To be fair, Trixie tried to stop herself before going down this route, but her muzzle worked of its own accord. Her retort was too smooth and sharp to grasp, like a flung blade, and it hit its mark with a sickening impact. "Because I believe the last time we met, it was you darkening your fair town, 'Nightmare Rarity'."
Rarity felt her stomach drop at the reminder. She didn't see Trixie visibly back off after she'd spoken words that she knew were going too far, like asking Princess Luna how the view from the moon was. Recognizing an emotional trigger when she saw one, Trixie started to extend a hoof in placating gesture. "Look, Rarity, I-"
The blue foreleg was swatted away sharply. With no energy or intonation, but with a frigid finality, she spoke clearly before turning and walking off, the calm on the outside doing little to hide the inner tempest.
"Stay out of my way, Trixie. I won't repeat myself."