This hands-on workshop is intended for beginners or for those who, like me, did Mineralogy
201 or its equivalent many years ago and find (also like me) that they have forgotten
practically everything. I had to do a considerable amount of brushing up to prepare for this
workshop!

We will start with a short talk and practical demonstrations to show how crystals and
crystalline materials are constructed, why some shapes are possible but not others, and how
all of them fall into one of seven groups known as crystal systems. If you have ever played
with children’s building blocks, or used bricks to build a wall or tiles to make a floor, you will
find all this very straightforward. Having become experts at recognising crystal shapes we will
divide into groups for the following activities:
- Using your newly acquired expertise, examine and describe real crystals from the
collection in the Tate Museum in hand specimen and under the microscope.
- Under a microscope, watch crystals actually growing and taking on their characteristic
shape.
- Use black boxes to observe the property of fluorescence (glowing in the dark under
ultraviolet light) in a variety of samples. A surprising number of minerals have this
property, including of course fluorite. (“Fluorescence” means “becoming like the flux”,
the flux in this case being fluorite, sometimes used in smelting or metallurgy.)
- Observe the phenomenon of birefringence (crystals that make you see double!)

And of course browse around the Tate Museum and enjoy our wonderful mineral collection.
On account of limited space and equipment the number of participants will be limited to 12. In
the event of more people wishing to participate, I am happy to hold a repeat session in the
afternoon.
Sign the sheet at our July meeting or contact me if you wish to participate in this workshop.
Frances Williams