The confirmed mechanic
Per the official store page, judging a raw stone involves three steps: shine a light on it, scrape the skin, and open windows to reveal the jade quality hidden inside. You can stop at any point — cash out with what you've confirmed, or keep cutting for more, at the risk of finding nothing or ruining the stone. The store page's tagline: "one cut can make your fortune, one cut can wipe you out."
What the achievements confirm
- A dedicated appraisal lamp exists — you can check a stone under it before buying (achievement "Truth Under the Lamp" / 灯下才说真话).
- "Windows" are tracked as a percentage of the stone opened — one achievement rewards accepting a good offer after opening less than 30% of a stone's window.
- Stones can end up cracked, with a repair glue item to fix them.
- A hard-mode achievement ("Judging by Eye Alone" / 肉眼凡胎) requires clearing a chapter without the lamp, glue, or a collector's card — implying all three are optional aids.
Unconfirmed
Exact odds of different jade grades, the cash cost of the lamp or opening a window, and how "skin scraping" differs from "opening a window" mechanically are not published anywhere official yet.