Note: This guide is a work in progress. We’ll update it as we discover new locations.
Where to find Glass Gemstone in FFXVThe Glass Gemstone that is probably the most accessible is in Lestalum Outpost. When you park the Regalia, go up the stairs. Now, cross the road to the left, towards the blue Newfields building. The item is next to one of the tables on the building’s front porch.
One of the locations where you can find a Glass Gemstone is in Cape Caem, near the Hidden Getaway rest spot. Face the entrance to the hotel and turn to the right. You’ll see a well not far off, and the item is sitting on the edge of the well.
Another Glass Gem location is in Altissa, the beautiful, Venice-lookalike city on the sea. The item itself is near The Leville – Royal Suite lodgings. Turn left when you exit the hotel and past the vendor. Take a left near the small fountain. Follow the path and you’ll see a small, square archway between a green door and a staircase going up. The item is on the ground in the archway.
Note: There is also one at Old Lestallum. It is north of the outpost immediately left of the stairs next to a small tree. (Thanks LEGENDSandLIONS)One more way to get a Glass Gemstone is by leveling Gladiolus’s Survival skill. Once it’s up to about level six, he’ll be able to get a Glass Gemstone as a drop after a battle. This is the long way to go about this, but it’s up to you how you choose to approach it.
Since Glass Gemstones are a treasure item, it’d be easy to assume its only worth is selling it for gill. This is far from correct, and the same is true for many other treasure items. The Glass Gemstone is vital to completing the . Once you acquire the item, go to Cid and he’ll upgrade your Engine Blade II. Of course, you need to have completed the first, for which you need a .