General terms:

* Dull: Lacking any shine or reflectivity.

* Earthy: A rough, unpolished appearance, like soil.

* Resinous: A waxy, gum-like appearance.

* Silky: A soft, shimmering appearance, like silk.

* Vitreous: A glassy, shiny appearance.

More specific terms:

* Adamantine: A very brilliant, almost diamond-like luster.

* Pearly: A soft, iridescent luster, like pearls.

* Greasy: An oily, greasy appearance.

* Submetallic: A dull, metallic-like appearance.

Other descriptions:

* Waxy: Similar to resinous, but with a slightly more translucent appearance.

* Porcelain-like: A smooth, white, opaque appearance.

* Chalky: A soft, powdery appearance.

Note: Some minerals can have multiple luster characteristics. For example, a mineral might have a dull appearance overall, but show a silky luster when fractured.