Crystal In Handmade Jewelry - Part Two: Crystal versus Glass Structure

Our 11" Suncatcher Talisman showing
off a variety of crystalline solids, such
as a smoky quartz faceted crystal
teardrop.

In Part One of my series of posts on 'crystal' I talked about many of the different definitions and uses for this common word in handmade jewelry business.  As this series continues, I am going to focus on each of the various views of 'crystal' and hopefully dispel some of the ambiguity.

A common place to find confusion is in the use of 'crystal' versus 'glass' in the materials listed for a handmade piece.  To a geologist, these terms have a specific difference based on structure.  To a bead artist, these terms are more likely to be differentiated based on chemical content.  Let's talk about structure first ...

'Glass' is a solid substance where the structure of the atoms is irregular and amorphous (and which will turn into a liquid when enough heat is applied).  There is no large scale order to be found in 'glass'.  Conversely, the structure of a 'crystalline' solid is very regular.  The internal matrix of a crystal is repetitive and highly ordered.

It is possible to have a 'glassy' form of a material that has the exact chemical composition as a 'crystalline' form.  The most most well known crystal is quartz, made of silicon and oxygen, SiO2, in a nice repeating pattern.  But SiO2 is also the major constituent of 90% of the glass in our everyday lives.  A crystalline substance can be formed by cooling a liquid slowly, allowing the atoms to line up into a nice, repeating pattern as the stuff becomes solid.  A glassy substance can be formed by cooling a liquid very quickly.  The stuff becomes a solid before the atoms have time to line up.

This means that any 'crystal' in a necklace need only be made of a solid with a repeating structure to be referred to as 'crystal'.  A designer that uses quartz crystal in a necklace will call it crystal, and be absolutely correct.  Yet this can be misleading if you imagine all crystal means 'Swarovski.'

I'll post soon about crystal versus glass - composition!

Jennifer