MicrobeHunter.com Microscopy Forum

Hi. I haven't been here for a while. I have been very busy with other academic related issues. I have been putting together some equipment for dark-field stuff. This is my first attempt. Sugar using an older Nikon microscope c1960s I think. I simply used a standard Olympus 4X objective with ~150mm extension between the microscope objective and a Nikon D200 camera flange. The magnification is around 10X I think.

Welcome back.....Looks good to me... I have always been partial to dark field.. Keep up the good work...

BillT

Hi again. Because I am studying how to identify various artefacts found in archaeological assemblages I thought to experiment with the crystal structure of sugar was a good and accessible place to start. I have added another image using a slightly different technique (still kind-of dark field) with much greater magnification. Notice the very obvious hexagonal crystallography. I am about to look at what crystals can be found in low temperature fired ceramics. Watch this space.

Your photos are just getting better and better.. You have my full attention now!... What archaeological assemblages are you looking for?... Very interesting subject, to me anyway....


The Best,
BillT.

I am studying at the master's level archaeology where my interest is attaching a cultural ideology to archaeological assemblages. My interest includes experimental archaeology whereby contemporary analogous experiments can offer a means to empirically validate hypotheses. Or at least, until further evidence becomes available. Archaeological assemblages consist of static objects that represent dynamics in the past so I look for meaningful ways of giving dynamics to the static artefacts. The pair of images I have attached today, I created yesterday, of contemporary earthenware ceramics (terracotta) whereby quartz sand has been added as a Grog/temper to reduce shrinkage and add strength. Because there is no sign of the crystal structure in these images the suggestion is that at microscopic level one could hypothesise that if archaic pottery is analysed to ask questions about human cognition and agency one could expect similar structural characteristics however I would suggest that the archaic artefacts may exhibit evidence of the crystal structure. Of course, this is only speculative at the moment but gives direction to the investigation. I should point out that the images are not brilliant but do begin a conversation as to our ancestors behaviour.

Are you suggesting that the human cognition was anything more than to use what was available at the time, or just using what worked for particular pots?

Sounds like you have chosen a rather difficult project.. Looks like it will require a large amount of samples to assay... Good luck!.. I would be interested in seeing more of your photos from time to time..

Regards,
BillT

georgetmacro wrote:Because there is no sign of the crystal structure in these images the suggestion is that at microscopic level one could hypothesise that if archaic pottery is analysed to ask questions about human cognition and agency one could expect similar structural characteristics however I would suggest that the archaic artefacts may exhibit evidence of the crystal structure.

I am really curious what you mean by this. I am not sure what you are expecting to be particularly different between quartz sand sourced today and quartz sand sourced by ancient people. If the question is whether ancient peoples were intentionally adding quartz as grog, or whether the quartz was just an incidental component of the clay they were using, the shape of the quartz grains is not going to help you answer it.

Scarodactyl.
What you say is absolutely correct. If the quartz sand from the area is established to correlate proportionately with the clay used at the time than one could assume that the quartz was not added intentionally, however, we know for a fact that in contemporary clay, the quartz is added for strength and to reduce shrinkage. My question is to establish if our ancestors worked out that adding the quartz sand gave an added beneficial effect that would not have happened if they had not. My coordinator seems to think that they did add the sand as you suggest. That being the case there is no reason to think crystal structure would be apparent unless they used actually crumbled quartz not common sand. I guess what can be investigated is whether geologists today can answer whether the proportions in the natural clay were the same as that of the finished artefacts? The crystal-structure part of the question may be completely unnecessary. Interesting just the same. Thanks for your valuable comment. Cheers George.

Yeah, you wouldn't see crystal structure in any case, quartz just fractures like glass. Some crystals (like salt or feldspar) show cleavage planes when they break which can tell you about the crystal form but quartz isn't so obliging.

There has been long-distance trade in pots for at least 2000 years. So unless you have found the dump of a pottery, how can you tell where the fragments originate from, if the basic ingredients also could be imported frome elsewhere? My not-to-be-trusted assumption would be that clay is the product of a sorting process and therefore normally should not contain coarse sand. On the other hand, potters are likely to be very specific about the clay they use and why not to use that single spot where clay and sand got mixed up... Then it might be hard to establish how much sand the clay contains in the area of origin, if the diggers are not aselective, and the clay deposits not homogenous. I am living where the sand 's cut off by the river (clay) that intruded the vally (peat) many times. It is a mosaic of soil compositions.

Hi George,

I hope you will continue to make updates on this very interesting subject...

BillT

billbillt. If you are interested in the direction archaeology is taking us regarding a better understanding of Hominin cognition and my thoughts on the subject have a look at my ongoing website
https://www.archaeology.vip

Will do.. Thanks for the link... I have a keen interest in this type of research..

Warmest Regards,
BillT

An interesting read..

https://nmnh.typepad.com/rogers_archaeo ... b/science/

BillT