In the gemstone trade, an assorted lot like this is called a parcel, a term that goes back to old mining practice, where sorting every single stone by type wasn't economical, so material got grouped and sold together in bulk sacks instead.
That's essentially what's happening here. Rather than running one variety through a cutting batch, several natural stones, agate, jasper, tiger's eye, amethyst, and others depending on what's currently in stock, get cut and finished together into one mixed parcel.
What's worth knowing upfront is that this isn't leftover or lower grade material being repackaged.
Every stone included is still cut to AAA finish individually, it's simply sold unsorted by type rather than separated into single variety batches, which is also why it costs less per carat than buying the same stones individually.
The trade off is predictability. You know the weight and piece count you're getting, but not the exact mix, since it depends on what's moving through the cutting house at the time your order is filled.
That unpredictability is actually why designers use parcels this way on purpose. It's a fast, low commitment way to test several stone types in real jewelry settings before deciding to buy bulk quantities of just one, and it's how a lot of resellers stock variety without carrying inventory across a dozen separate single stone listings.
For anyone newer to working with gemstones, handling a genuine mix like this, feeling the weight and finish differences stone to stone, teaches more about material selection than reading a spec sheet ever could.