Start with what origin means
A laboratory-grown diamond is formed through a manufactured growth process. A mined stone is extracted from the earth. Both should be represented with clear origin language.
Origin is not a quality grade. The same cut, color, and clarity scales apply to both, and a report from an independent laboratory states which one you are looking at.
Where the difference shows
The visible difference is usually price and availability rather than appearance. A laboratory-grown diamond of a given specification is generally less expensive, which is why the same budget often buys a larger or better-cut stone.
Resale behaves differently too. Neither category is bought as an investment, and a piece should be chosen because it will be worn.
Keep claims specific
Origin describes how a stone was formed. Broader environmental or sourcing claims require their own documented evidence and should not be inferred from origin alone.
Ask for the claim, not the adjective. A grading report, a stated growth method, and a named manufacturing partner can all be checked. A word like responsible cannot.