NARSARSUKITE
(narsarsukite are the greeny/yellowy crystals in the matrix; this is from Mont St-Hilaire, Quebec, Canada)
[(Na,K)6(Y,Ca)2Si16O38 · 10H2]
Narsarsukite is relatively common at Mont St-Hilaire, where one can find some of the finest and largest specimens for the species. It occurs in the quarries and in outcrops of weathered hornfels on the north flank of the mountain.
Hardness: 6 - 7