Luster, also spelled lustre, is a simple word for a complex thing: the way light interacts with the surface of a mineral. This gallery shows the major types of luster, which range from metallic to dull.
I might call luster the combination of reflectance (shininess) and transparency. According to those parameters, here is how the common lusters would come out, allowing some variation:
Metallic: very high reflectance, opaque
Submetallic: medium reflectance, opaque
Adamantine: very high reflectance, transparent
Glassy: high reflectance, transparent or translucent
Resinous: medium reflectance, translucent
Waxy: medium reflectance, translucent or opaque
Pearly: low reflectance, translucent or opaque
Dull: no reflectance, opaque
Other common descriptors include greasy, silky, vitreous and earthy.
There are no set boundaries between each of these lusters, and different sources may classify luster in different ways. Additionally, a single category of mineral may have specimens within it with different lusters. Luster is qualitative rather than quantitative.
Metallic Luster in Galena
Galena has the real metallic luster, with every fresh face like a mirror.
Metallic Luster in Gold
Gold has a metallic luster, shiny on a clean face and dull on a worn face like this nugget.
Metallic Luster in Magnetite
Magnetite has a metallic luster, shiny on a clean face and dull on a weathered face.
Metallic Luster in Chalcopyrite
Chalcopyrite has a metallic luster although it is a metal sulfide rather than a metal.
Metallic Luster in Pyrite
Pyrite has a metallic or submetallic luster although it is an iron sulfide rather than a metal.
Submetallic Luster in Hematite
Hematite has a submetallic luster in this specimen, although it can also be dull.
Adamantine Luster in Diamond
Diamond shows the definitive adamantine luster (extremely shiny, even fiery), but only on a clean crystal face or fracture surface. This specimen has a luster better described as greasy.
Adamantine Luster in Ruby
Ruby and other varieties of corundum can display an adamantine luster owing to its high index of refraction.
Adamantine Luster in Zircon
Zircon has an adamantine luster owing to its high index of refraction, which is second only to diamond.
Adamantine Luster in Andradite Garnet
Andradite can display adamantine luster in high-quality specimens, which led to its traditional name of demantoid (diamondlike) garnet.
Adamantine Luster in Cinnabar
Cinnabar displays a range of lusters from waxy to submetallic, but in this specimen it is closest to adamantine.
Glassy or Vitreous Luster in Quartz
Quartz sets the standard for glassy (vitreous) luster, especially in clear crystals like these.
Glassy or Vitreous Luster in Olivine
Olivine has a glassy (vitreous) luster that is typical of silicate minerals.
Glassy or Vitreous Luster in Topaz
Topaz displays a glassy (vitreous) luster in these well-formed crystals.
Glassy or Vitreous Luster in Selenite
Selenite or clear gypsum has a glassy (vitreous) luster, though not as well developed as other minerals. Its sheen, likened to moonlight, accounts for its name.
Glassy or Vitreous Luster in Actinolite
Actinolite has a glassy (vitreous) luster, although it can also look pearly or resinous or even silky if its crystals are fine enough.
Resinous Luster in Amber
Amber is the typical material displaying resinous luster. This term generally is applied to minerals of warm color with some transparency.
Resinous Luster in Spessartine Garnet
Spessartine garnet can display the golden, soft sheen known as resinous luster.
Waxy Luster in Chalcedony
Waxy Luster in Variscite
Variscite is a phosphate mineral with a well-developed waxy luster. Waxy luster is typical of many secondary minerals with microscopic crystals.
Pearly Luster in Talc
Talc is well known for its pearly luster, derived from its extremely thin layers that interact with light penetrating the surface.
Pearly Luster in Muscovite
Muscovite, like other mica minerals, gets its pearly luster from the extremely thin layers beneath its surface which is otherwise glassy.
Dull or Earthy Luster in Psilomelane
Psilomelane has a dull or earthy luster owing to its extremely small or nonexistent crystals and lack of transparency.
Dull or Earthy Luster in Chrysocolla
Chrysocolla has a dull or earthy luster, even though it is vibrantly colorful, owing to its microscopic crystals.
Glassy or Vitreous Luster – Aragonite
Aragonite has a glassy (vitreous) luster on fresh faces or high-quality crystals like these.
Glassy or Vitreous Luster – Calcite
Calcite has a glassy (vitreous) luster, although being a soft mineral it turns duller with exposure.
Glassy or Vitreous Luster – Tourmaline
Tourmaline has a glassy (vitreous) luster, although a black specimen like this schorl crystal is not what we normally think of as glassy.
CITE THIS ARTICLE
Alden, Andrew. “Examples of Different Mineral Lusters.” ThoughtCo, Feb. 16, 2021, thoughtco.com/examples-of-different-mineral-lusters-4122803.