Heat treatment uses controlled high temperatures to change a gemstone's colour or clarity. Treating an earth-mined stone does not make it lab-grown: origin and treatment are separate parts of the description.
Heated does not mean fake, and unheated does not automatically mean better. Colour, clarity, cut, origin, size and condition still matter. Treatment status is one part of the description, so read it alongside the other details for the lot.
Teals catalogues treated and untreated stones. When treatment is known, the lot names it plainly. Heat, oil, resin, irradiation and filling are different interventions, so the description uses the relevant term rather than grouping them together.
When our review of a stone's record identifies no treatment, the lot says None Identified. That describes our review, not a laboratory finding, and it does not mean untreated. When the record leaves the question open, we flag it for review rather than fill the gap with a general assumption.
Natural on Teals means earth-mined, not unenhanced. A natural stone may still have been treated after mining. Naming treatment where it is known, and uncertainty where it is not, gives a buyer the facts needed to compare one stone with another.