The icon is made up of eight triangle shapes. The top five are all turned in different directions. The bottom three are made up of two obtus triangle at the left and right and the middle one looks like a isosceles. Together they all form a gem-shape.
This is a Jewel 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 13,300 icons, all in the same style and quality.