Crystals – Order Inside Solids

Tip a little table salt onto a dark plate and look closely, with a magnifying glass if you have one, and you'll find that every single grain is a tiny, near-perfect cube, formed with no human hand shaping it at all. This episode explores why solids sometimes arrange themselves this precisely, what a crystal lattice actually is, how crystals grow from solution and from molten rock, how shining X-rays through a crystal revealed the structure of DNA itself, why a thin slice of quartz can keep remarkably accurate time, why every snowflake is six-sided yet genuinely unique, and why "crystal healing" has no scientific basis at all.

You'll come away understanding what makes a crystal different from an ordinary solid, why crystals grow with flat faces and sharp angles, how crystals form from solution and from cooling melts, how X-ray crystallography works and what it revealed about the structure of DNA, what piezoelectricity is and how it's used in quartz watches, why snowflakes are six-sided but never identical, and why claims about crystal healing don't hold up against basic scientific scrutiny.

Talking Science is sponsored by Kinsoft. Visit www.kinsoft.com.au

Further reading: Royal Institution of Australia (Cosmos) and Royal Society of Chemistry – explainers on crystal structure and crystallography; Nobel Prize organisation – background on the discovery of DNA's structure and the contribution of X-ray diffraction; Scientific American – features on piezoelectricity and snowflake formation; CSIRO – public science resources on minerals and materials science.