Testing Metallic Lustre: Metal vs. Non-Metal

[jordyjordyjordy]

hey does anyone know how you can carry out an experiment to find out if a metal or non-metal has a metallic lustre?

i have tried looking all over the internet but i can't find anything...
if u could post answers or terms i can place into the google search panel it would be greatly appreciated

please and thank you

 

[Astronuc]

Well it is apparently difficult to find online a discussion of how to determine the 'lustre' of a metal or mineral.

Here is a discussion of 'lustre', but in addition to metallic there are other classifications: adamantine, vitreous (like glass), resinous (like amber), waxy (like jade), greasy (like soapstone), pearly, and silky.

http://en.wikipedia.org/wiki/Lustre_(mineralogy)

http://www.1911encyclopedia.org/Mineralogy

Introduction to Mineralogy
http://isis.ku.dk/kurser/blob.aspx?feltid=84117 - this might be useful in conjunction with the others.

See slide 14/16 - Lustre

Coefficient of reflectivity: R = [(n-1)2+n2K2]/[(n+1)2+n2K2]
n = refractive index, K = coefficient of absorption
R is proportional to both!

Types of lustre and examples:
Metallic (gold, graphite, galena, chalcopyrite, pyrite, hematite, magnetite)
Submetallic (sphalerite, ilmenite)
Adamantine (diamond, sphalerite, corundum, goethite, biotite)
Vitreous (rutile, halite, calcite, aragonite, dolomite, apatite, olivine, quartz)
Resinous (sphalerite, apatite, opal)
Pearly (aragonite, gypsum, muscovite)
Greasy (serpentine, nepheline)
Silky (goethite, gypsum, serpentine)
Earthy (graphite, hematite, goethite, kaolinite)


Spectroscopy seems to be the answer, otherwise one must use one's eyes and learn the skill from a experienced mineralogist/metallurgist/material scientist.