Sunday, March 22, 2009

LPoD - dichroic glass

Today's learning point relates to the bracelet I received for mothers' day. It is made of beads of dichroic glass, which appear to change colour, depending on the angle at which you view them.

Dichroic coating was originally developed by NASA for the aerospace industry. The material is used in the visors of space helmets. I have also heard some reports that it is used in the Hubble telescope, but I have been unable to verify this. The glass contains microlayers of different metal oxides, applied using an electron bombarder inside a vacuum chamber. These reflect and refract light in different ways, resulting in the effect of different colours when it is tilted this way and that. In fact, no color is actually produced. The perceived colours are the result of light manipulation.

It is now very popular in costume jewellery design and manufacture, as much because of the price tag as the depth and range of colours. Because the reflection/refraction cannot be accurately predicted, no two pieces of dichroic glass are ever exactly alike.

Here's an example, picked at random from the many returns from a google search.

2 comments:

Anonymous said...

Love the dichroic glass - it's the poor man's fire opal which are also a thrill for the eyes! I only know of these little miracles of nature because my sister uses them in her jewelry (scroll down to see) -- not because I can afford them! Dichroic glass works for me! :)

Have you seen these which are also made of glass? They are fascinating. I bought my daughter a book by this guy and his Cinespinners are pretty cool too. I think I might have to have the sea turtles...

Cindy

Karyn Romeis said...

@cindy I once had a fire opal. It was given to me by a woman who hardly knew me, just because she thought it suited me. I gave it to a jeweller to set for me and the blighter made off with it. I was gutted.

Your sister's stuff is lovely. I like the tree design. I hadn't seen the flip books you linked to, but I've seen similar ones before. Pretty amazing!