This is a Hourglass Filled 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 12,900 icons, all in the same style and quality.
It's a logo of an Hourglass, reduced to an image of an Hourglass. An Hourglass looks like the two wine cups held together without their stems in opposite directions. After the glass there is something to hold the matter in place in order to tell time.