"Are you. . .sure it's not real?" He asked, even as he gave it a hesitant whiff. It didn't smell like gems, but. . .
The Professor chuckled. "Sure as I am the sun is up! It's a simple recipe of crystallized sugar, and some added nutrient supplements. Should taste sweet, maybe a little fruity or tangy!"
Spyro eyed it skeptically, flapping his wings once, nervously. "If you're sure. . ."
The Professor hummed but didn't push him; instead, he turned back to his experiments and calculations, letting Spyro get a feel for it. Elora was out collecting some stuff for the Professor and Hunter was 'stealthing it up', so it was just the two of them, and while the dragon seemed much better since his initial captivity, he still had a gaunt, stunted look to him. Action had to be taken, and today was the perfect day.
Hence the Imitation Gems. Also called Crystal Sugar, and Rock Candy, in some worlds.
The Professor had been struck with the idea after Spyro explained more about Crystals and Gems to the three of them - Crystals being more structured and energized, which they destroyed to absorb energy from, which increased their 'breath power', whereas Gems (which had monetary value to those outside of the Dragon Realms) were more like mini energy 'heaters'. Sort of similar to the Professor's magic orbs. (Unfortunately, since they don't drain or dissipate like crystals, other creatures like Gnorcs can take them and create Gem-bound Creatures, which are an absolute annoyance.)
So, the idea can forth from that. That Dragons take energy from such things. And the Professor happened to know a food-like object that looked similar, and perhaps with the comfort of a familiar object. . .
It was an idea, anyway.
For now, though, Spyro was wary. Not distrusting, which made the Professor's heart glad. Just. . .a sort of general confused wariness.
He continued on with his project; the scant information Spyro understood about his Home realms helpful enough for the mole to need to tweak his calculations. He got so absorbed in his work, that the eventual crunch made him jolt.
None-to-subtly (fortunately the young dragon didn't notice), he peeked over his shoulder. Sure enough, sat, hunched down like a cat, Spyro was trying some of the Crystal. It made a tinkling crinch as he bit, slowly, taking his time. After a bit, he seemed to make a decision and started eating at a more normal rate.
The Professor sighed quietly, relieved. He even caught sight of Sparx, settled on the ground near his brother, give him a slight nod.
He turned back to his work, and began to hum a tune.
Seemed things were beginning to look up.