vug

地质学家的锤子敲开岩石，露出一处布满紫水晶晶簇的晶洞。

The geologist's hammer broke open a rock to reveal a ___vug lined with amethyst points.

矿山中一处被切开展示的晶洞在大学矿物陈列馆里展出。

A cross-sectioned ___vug from the mine was displayed in the university's mineral gallery.

手电筒的光束照出洞顶上一处昏暗的晶洞，从步道上几乎看不到。

Flashlight beams revealed a dark ___vug in the cave ceiling, barely visible from the trail.