<p>A study was conducted to evaluate the effect of glycine concentration on lithium extraction from calcined pegmatitic samples, aiming to propose a green hydrometallurgical route to replace highly corrosive media. In Mexico, pegmatitic lithium deposits represent an emerging industry; however, conventional extraction methods for these minerals require the use of hydrofluoric and sulfuric acid solutions, which involve high operational costs, specialized equipment, and significant environmental impact in areas surrounding mining operations. In response to this issue, the acidic leaching stage is proposed to be replaced by the use of a biodegradable organic ligand that allows selective lithium leaching and facilitates its reintegration into natural cycles. The mineral samples were chemically and mineralogically characterized, confirming the mineral phases by XRD and SEM–EDS techniques. Additionally, lithium content was determined in Kunzite (3.36 wt%) and Lepidolite (1.68 wt%) by ICP and LIBS. The theoretical operating conditions were established through Pourbaix diagrams, optimized structure simulations, and Job’s method. A thermogravimetric study of both samples was also conducted, establishing that the pyrometallurgical pretreatment is a key step to ensure the structural change of the pegmatitic species. Finally, a maximum lithium dissolution of 71% was achieved from calcined Lepidolite powders using [Gly] = 1.5&#xa0;mol L⁻¹, and 56% lithium complexation from calcined Kunzite powders with [Gly] = 2&#xa0;mol L⁻¹. Reaction order calculations indicate that the system with the highest dependence on glycine concentration corresponds to calcined Lepidolite (n = 0.91), positioning this mineral as the best source for lithium extraction in this green leaching system.</p> Graphical Abstract <p></p>