Gemstone skin should include an icon
Gemstone skins are very rare in league, costing upwards of $300 dollars to get due to the rarity of getting the gemstones from hextech loot specifically. With this rarity they should definitely be in consideration to come with some other reward for unlocking. An icon would be a very interesting way to do this as you could showoff an exclusive icon only obtained through the gemstone system. This isn't too much of a request given the cost you have to put in to unlock a gemstone skin, and also because an icon is about the smallest request we can make as players. An ultimate skin costs around $25, the benefits given for ultimate skins make the gemstone skins very underwhelming given their substantial cost. This is not a free reward like others suggest, this is a benefit from unlocking something that takes a ton of time, luck, or money to unlock, and i personally believe an icon should be included with skins that rare.
Credit to the original idea: https://www.reddit.com/r/leagueoflegends/comments/8jbvy5/would_be_cool_to_have_summoner_icons_based_around/