Lustre and Glossy
In mineralogy, the word lustre is used to describe the way that a crystal surface reflects light.lustrous There are different kinds of lustre, depending on the crystal's refractive power, diaphaneity, and structure. A crystal's lustre may be earthy, metallic, greasy, silky, or vitreous. In general, a mineral with high lustre will have a more reflective surface than one with low luster.
The lustre of a diamond is its ability to reflect light in a way that seems to glow, sparkle, and shimmer.lustrous The color and brightness of a diamond's luster depends on its composition. For example, a diamond with a yellowish tint is more common in nature than a dark gray diamond. In addition, the lustre of a diamond will vary according to its size and shape. Whether a diamond is lustrous or dull is also determined by its atomic structure. A rough diamond will have a more dull luster than a polished diamond.
Scientists have discovered a new type of paint that can make surfaces look lustrous, but it isn't quite ready for commercial use. The new material is a chloride-doped oligomer that can be coated on glass to give it a metallic sheen without the need for any metal or phosphor particles. The lustrous coating also has good durability. However, the team behind it found that the oligomer had an annoying side effect: it left a dark stain on glass plates that looked like a coffee ring. The scientists say that they will need to work out how to prevent this staining in order to have the luster paint be used for commercial purposes.
To determine whether there is a temporal segment of the binocularly combined intensity functions that elicits lustrous appearances, we presented the stimuli in 19 conditions. The bottom row of Figure 8 shows the predictions based on each of the three simple mechanisms: mechanism A (left), mechanism B (middle), and mechanism C (right). Each of these predicts a specific threshold value of the difference in the temporal slope of the left- and right-eye input that is required for lustrous appearances.
This qualitative comparison of the phenomenological regularities associated with lustrous appearances in the three distinct mechanisms reveals that, for our viewing conditions, the presence of a counter-modulation is the relevant image parameter for lustrous appearances. This contrasts with the conclusions of a luminance-based neural conflict theory and a classical Oppel-Helmholtz explanation, which suggest that the core physical regularity of differential binocular input associated with lustrous appearances is a form of a spatial increment-decrement pairing between eyes. The asymmetry in the propensity for lustrous appearances between the black and grey surround conditions suggests that this pairing is exploited at a lower threshold than for the white surround condition, in which case a less steep slope of the temporal intensity modulation function is needed to yield a lustrous appearance. However, it is possible that the asymmetry could be explained by the presence of a different physical regularity that could not be identified in our experimental design.