前寒武紀，古生代

化學組成, 鍵及結構：(礦物)

Precambrian-Paleozoic

Chemical composition, bonding and structure: (Mineral)

高溫會使岩石晶體融化並重新結晶成新的岩石。 在聚合性板塊邊緣環境中，熱和化學活動將頁岩和泥岩的粘土礦物轉化為板狀雲母礦物，如白雲母，黑雲母和綠泥石。 定向壓力將轉換中的粘土礦物從它們的隨機的排列推到平行排列中，其中板狀礦物的長軸垂直於壓縮力的方向取向。 礦物的這種轉變標誌著岩石不再是沉積而是變質岩石。

原生物：(化石)

High temperature can make rock crystals melt and recrystallize into new rock. In the convergent plate boundary environment, heat and chemical activity transform the clay minerals of shales and mudstones into platy mica minerals such as muscovite, biotite, and chlorite. The directed pressure pushes the transforming clay minerals from their random orientations into a common parallel alignment where the long axes of the platy minerals are oriented perpendicular to the direction of the compressive force. This transformation of minerals marks the point in the rock’s history when it is no longer sedimentary but becomes metamorphic rock.

Living Specimens: (Fossil)

顏色：有光澤，中等灰色

質地：葉片狀

成分：白雲母，黑雲母，石榴石，石英，長石

顆粒尺寸：細至中等粒度

硬度：一般很硬

Color: Shiny, medium gray

Composition    : Muscovite, Biotite, Garnet, Quartz, Feldspar

Grain size: fine to medium grained

Hardness: generally hard

作為建築材料：片岩不是工業用途廣泛的岩石。 其豐富的雲母顆粒和片理使其成為一種低物理強度的岩石，通常不適合用作建築材料，建築石材或裝飾石材。 當材料的物理屬性不合適時，唯一的例外是它用作填充物。

作為寶石材料的基石：

片岩通常是變質岩中形成的各種寶石的主要岩石。 在片岩中發現了寶石質量的石榴石，藍晶石，坦桑石，祖母綠，紅柱石，藍寶石，紅寶石，閃石，堇青石，金綠寶石和許多其他寶石材料

As a Construction Material: Schist is not a rock with numerous industrial uses. Its abundant mica grains and its schistosity make it a rock of low physical strength, usually unsuitable for use as a construction aggregate, building stone, or decorative stone. The only exception is for its use as a fill when the physical properties of the material are not critical.

As a Gem Material Host Rock:

Schist is often the host rock for a variety of gemstones that form in metamorphic rocks. Gem-quality garnet, kyanite, tanzanite, emerald, andalusite, sapphire, ruby, scapolite, iolite, chrysoberyl and many other gem materials are found in schist.

因弗內斯郡，蘇格蘭，南島

Inverness-shire, Scotland, South Island