Tempered glass gems can withstand extreme heat. Uniform in size and shape. Luster-enhanced colors bring added shimmer. Can withstand temperatures up to 1800°F. Adding handfuls of these Glass Fire Gems will not only revitalize the look of your fire-side experience, they'll also boost the magic of a flickering fire in channeled gel and ethanol burners. These fire gem colors can be combined for incredible depth, iridescence and contrast. . . . Can withstand temperatures up to 1800 degreesFMade in the USA.