Forensic microcrystalloscopy: a timeless tool in toxicology or a relic of the past

Microcrystalloscopy, though often viewed as a historical technique, continues to offer unique advantages in forensic and toxicological analysis. Its ability to provide rapid, low-cost, and visually distinctive identification of chemical compounds makes it especially relevant in contexts where high-end instrumentation is limited or unavailable. Originally developed in the 19th century, the method gained formal forensic recognition through the work of Maria Dmitrievna Shvaikova, whose legacy remains foundational to the field. In commemoration of Shvaikova's 120th anniversary, we call for renewed scientific attention, collaborative standardization efforts, and broader educational inclusion. Far from being obsolete, microcrystalloscopy represents a flexible, underutilized asset with continued relevance in global forensic science. This review re-examines microcrystalloscopy through a modern lens, highlighting how its core strengths: morphological specificity and operational simplicity, can complement contemporary analytical techniques. We explore recent advancements that are reshaping the method's application. Special attention is given to its evolving role in detecting synthetic drugs, toxicants in biological fluids, and adulterated drug mixtures. Looking forward, we argue that microcrystalloscopy's future depends not on competing with gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-tandem mass spectrometry (LC-MS/MS), but on serving as a strategic, complementary tool within a tiered analytical framework.