黝帘石是钙铝羟基孤立双四面体矿物，也是硅酸盐矿物，属于绿帘石组群。

黝帘石是由斯洛文尼亚科学家西格蒙德·佐伊斯男爵命名的。1805年，矿物经销商西蒙·普雷森在斯洛文尼亚柯罗斯卡地方的沙乌阿皮山发现了它，西蒙把这矿物带来给男爵。确定石头类型之后，男爵起初命名为saualpite。黝帘石蕴藏于变质岩以及结晶花岗岩岩脉中，以多彩的正交晶系晶体或是以大团块的形状呈现，黝帘石有多种颜色，有：蓝色、紫罗兰色、绿色、褐色、粉红色、黄色、灰色或无色。

黝帘石的硬度超过莫氏硬度6级，比重约在3.10~3.38之间，视乎不同的石种。

Zoisite, first known as saualpite, after its type locality, is a calcium aluminium hydroxy sorosilicate belonging to the epidote group of minerals. Its chemical formula is Ca₂Al₃(SiO₄)(Si₂O₇)O(OH).

Zoisite occurs as prismatic, orthorhombic (2/m 2/m 2/m) crystals or in massive form, being found in metamorphic and pegmatitic rock. Zoisite may be blue to violet, green, brown, pink, yellow, gray, or colorless. It has a vitreous luster and a conchoidal to uneven fracture. When euhedral, zoisite crystals are striated parallel to the principal axis (c-axis). Also parallel to the principal axis is one direction of perfect cleavage. The mineral is somewhat higher than 6 in hardness, and its specific gravity ranges from 3.10 to 3.38, depending on the variety. It streaks white and is said to be brittle. Clinozoisite is a more common monoclinic polymorph of Ca₂Al₃(SiO₄)(Si₂O₇)O(OH).