This is a Quest icon. We've made it in iOS style, first introduced in iOS version 7 and supported in all later releases up until now (at least iOS 11). This style is based on thin two-pixel lines and is optimized for 50x50 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 12,500 icons, all in the same style and quality.
It is an geometric shape, a flat rectangle that has been pushed from either side to cause it to bend up in the middle. The bending has been done neatly, creating sharp angles, forcing the center of the bend into a point along the middle. There is a question mark in its center.
Related to Quest Icon
Related icons are the icons with matching tags, as well as all maps icons. All icons are in the same flat style. You can either download free PNG icons or buy SVG vectors