What is Crystallography?
In order to understand the history of it, we have to know what crystallography is. Crystallography is the study of crystals and the use of their atomic arrangement to understand their properties. Crystallography can be very useful. For example, it was used to track mutations and find a cure for COVID-19 (NIH). The spikes of the virus that allowed it to attach and infect your cells had a crystalline structure, meaning antibody treatments could target those spikes. The crystal spikes would also change slightly during mutations, allowing scientists to track new strands of COVID. Crystalline structures are also responsible for gemstones’ brilliance in light.
The Very Beginnings
All the way back in 1611, before the New York colony was founded in America, Johannes Kepler was interested in snowflakes. Despite not having atomic theory, he made an educated guess that the crystal structure of snowflakes was related to the hexagonal packing of spheres.
Source: (Wolfram)
Because snowflakes are always symmetric in six ways across their center, Kepler was able to conclude that crystal structures are related to the hexagonal optimal packing of spheres.
Steno’s Law and the Father of Modern Crystallography
Nicholas Steno, a 17th century Danish geologist, studied the formation of rocks on Earth. However, he most likely came across many gemstones in his time due to being around rocky areas. These gemstones, Steno postulated, all had the same angles between equivalent faces so long as they were the same type of gemstone. This meant crystals of the same molecules would always have the same structure, making it unique.
In the early 19th century, Rene Just Hauy, a french mineralogist, around the time John Dalton was publishing his theory of atoms, argued two things. First, that crystals have a fundamental unit that cannot be broken. Second, that crystals are created using a successive structure of these fundamental units, organized in a lattice. At the time, this was groundbreaking because people had no idea how to differentiate certain crystals. This began the widespread study of crystals.
The history of crystallography is a long story, so I will continue next week.
Leave a Reply