Gilashin ma'adini, wanda kuma aka sani da fused silica ko fused quartz, wani nau'in gilashi ne da aka yi daga silica zalla (SiO2) kuma ana siffanta shi da tsayin daka da juriya ga yanayin zafi. Ana ƙera shi ta hanyar narkewar kristal ɗin da aka niƙa ko foda a yanayin zafi sosai sannan kuma cikin sauri sanyaya narkakkar kayan don samar da gilashi mai ƙarfi. Ƙunƙarar ƙasa kuma ta ƙunshi silicon dioxide. Gilashin ma'adini yana da tsari na atomatik na musamman wanda ke ba shi damar samun abubuwan gani na musamman da na thermal. Ana amfani da shi sau da yawa a aikace-aikacen da ke buƙatar matakan tsafta, kamar a cikin kayan aikin kimiyya, masana'antar semiconductor, ruwan tabarau na gani, fiber optics, da kayan aikin dakin gwaje-gwaje.Kalmar "gilashi" yawanci tana nufin wani abu mai ƙarfi. wanda ba crystal ba ne kuma ba shi da tsari na atomic na dogon zango. Gilashin quartz, duk da haka, yana kula da tsarin atomic da aka ba da umarni sosai kwatankwacin na lu'ulu'u na quartz, wanda ke ba shi kaddarori daban-daban idan aka kwatanta da sauran nau'ikan gilashi.A taƙaice, gilashin quartz wani nau'in gilashi ne na musamman da aka yi daga silica mai tsafta kuma tana da kyakkyawan tsaftar gani da juriya ga yanayin zafi, yana mai da shi kima ga aikace-aikacen kimiyya daban-daban, masana'antu, da fasaha.