It's a logo of a Thin Test Tube. The beaker has a dark outline and is white in the middle. The beaker is small and has a liquid inside just past halfway.
This Experiment icon is made in Material Design style
developed by Google. This style is based on extremely simplified shapes, thin two-pixel lines, and is optimized for 24x24 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 5,700 icons, all in the same style and quality.