化學組成, 鍵及結構：(礦物)

不詳

Chemical composition, bonding and structure: (Mineral)

Unknown

原生物：(化石)

黑曜石形成時，熔岩從火山噴發出來並迅速冷卻。具體而言，由於熔岩走向地表，水分蒸發，導致岩漿加厚。其厚度使其移動速度。當冷卻過程減緩，晶體開始在平滑的玻璃形成的黑曜石。這些晶體含有石英核心，稱為球晶，並在其他黑色玻璃創造雪花。

Living Specimens: (Fossil)

Obsidian is formed when molten lava erupts from a volcano and cools rapidly. Specifically, as lava moves toward the Earth’s surface, the water content evaporates, causing the lava to thicken. Its thickness makes it move slower. When the cooling process is slowed, crystals begin to form in the otherwise smooth glass of the obsidian. These crystals , called spherulites, have a quartz core, and create the snowflakes in the otherwise black glass

黑曜石通常是黑色，棕色和紅色。雪花黑曜矅石含有白色或灰白色的雪花。石頭通常是光滑的，但將它切或鑿去就會形成鋒利的邊緣。雪花黑曜石是獨特的因為，不像其他的黑曜石，它不是純玻璃。因為它冷卻在比較冷的溫度下，它包含水晶片斷是技術上的岩石。同時，黑曜石幾乎完全沒有礦物晶體和岩石雜質。具體來說，黑曜石約百分之七十都是二氧化矽。

Obsidian is found in shades of black, brown and red. Snowflake obsidian is a black obsidian that contains white or white-gray flakes. The stone is generally smooth, but has sharp edges when cut or chipped away. Snowflake obsidian is unique because, unlike other obsidians, it is not pure glass. Because it cools at a cooler temperature, it contains crystal segments that are technically rock. Also, Obsidian has an almost total absence of mineral crystals and rock impurities. Specifically, obsidian is about 70 percent silica.

黑曜石已經被人類用於多種用途。從歷史上看，黑曜石的鋒利邊緣用於形成箭頭和切削工具。最近，它已被納入首飾石作為裝飾。

Obsidian has been shaped by man for several purposes. Historically, obsidian’s edges were sharpened used to form arrowheads and cutting tools. More recently it has been incorporated into jewelry as a decorative stone.

黑曜石在地面的上方和下方形成。當黑曜石在火山口上的形成，這通常是最高質量的黑曜石。當熔岩流從地下和地上，它也會形成在地面。黑曜石是唯一發現在有或已有火山活動的位置，並有較高的矽含量。在美國，它只發生在西海岸，並發現最突出的是在俄勒岡。

Obsidian forms both above and below ground. Below ground obsidian forms in volcanic vents; this is typically the highest quality obsidian. It also forms just on top of the ground surface when lava flows out of the ground and over land. Obsidian is only found in locations where there is or has been volcanic activity, and where there is a high silica content. In the United States, it occurs only along the west coast, and is found most prominently in Oregon.