Is there somewhere I can read about what those two are and what they do?

Breeding items that help you get a better foal

Sven (1 mill) : +2 stat points to all traits
Glass (100k) : +3 stat points to a trait (trait depending on which color you buy)
Medallion (330k): +2 stat points to a discipline

Yellow Glass: +3 Strength
Red Glass: +3 Heart
Purple Glass: +3 Scope
Orange Glass: +3 Speed
Green Glass: +3 Intelligence
Blue Glass: +3 Movement

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They cost quite a penny and a good chance you still end up with a bad foal.
Only buy / use them on a match you are sure of that can produce something good :)

Thank you so much!
I'm too inexperienced to be sure of my matches, so I definitely won't be using any of those for a long time. But thanks for clearing it up. :)