Aluminium Magnesium Silicate

You need to hire a chemist...

why?????

I am a chemist.But in this case I need help.

A Little Orientation Please

A Mesopotamian cuneiform tablet from the second millennium B.C. describes Tapputi, the first documented chemist. There is no shame in researching prior art. I suspect that SE agrees. He often says hire a professional when he thinks the task at hand is probably more challenging than the OP suspects. Pyrope is an indicator mineral for high-pressure rocks. High pressure chemistry is not, as you are most likely aware, a casual pursuit, particularly in combination with high temperature even for chemists if they are not specialized in those realms.

What sparks your interest in pyrope garnet ? What characteristics of the material do you want to use ? Garnet is a semiprecious gemstone when it has transparency and does not look like the picture provided for the by the pound product. Are you interested in its hardness for some abrasive purpose ? Do you actually want to synthesize it or is mining it OK ? What size pieces do you want ? At one time I was looking at garnet sand to use as an abrasive. If you want sand, do you want particles of a particular size or a particular mix of sizes ? Do you need a large quantity like tons or a small piece or two ? Are you wanting to make it more cheaply than other suppliers so you can sell it in quantity ? Are there other characteristics that you intend to optimize by producing it yourself, such as some electronic purpose ? Garnet sometimes has magnetic properties(probably if it has iron in it) which might be useful. Are you looking for high purity garnet so that you can dope it to various levels with impurities to investigate its magnetic uses ? Are you going to heat treat it to broaden its gem appeal ? The combination of magnetic behavior and abrasive capability might be useful for circulation of abrasive materials and separation from the remains of the material abraded. Do you want to use this combination of features ? The magnetic characteristics might enable garnet as a digital storage medium. I think there was at one time a magnetic bubble substrate based on garnet. Are you interested in that application ? Are you interested in tuning ε and μ to control the speed of light within the garnet ? I could go on and on and on. Basically, it would help if you could steer us by somehow describing why you want to make it and what characteristics it needs to exhibit.

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thewildotter

Then:

• please indicate where current research on the topic has come to an end so that the forum can offer guidance beyond the end of it.
• please also indicate why sufficient assistance is not available from resources that are currently to hand.

Sheesh! Not even mentioning quantities! Where on earth would a forum start (rhetorical question - NNTR)?

Yes, Mother Earth makes it in abundance. It is called Pyrope Garnet (Mg₃Al₂Si₃O₁₂)

Hard topic About this hard:

Mohs hardness: 7.5

But a quick peak at the web says you can easily buy it for about $14/lb.

I bet it is hard to make it that cheaply on the first try. The elemental

materials are fairly cheap but it needs ~40 kbar, 1400 °C, in graphite capsule per this source.

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thewildotter

Now, if you wanted to make some so you can become a healer Yogi, you could buy this impressive sphere for just a little more.

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thewildotter

So if it is available commercially, why on earth would one consider making it from scratch (rhetorical question - NNTR)? Ridiculous!

are you looking for a certain particle size or surface area? or do you just need to synthesis the stuff?

solid state synthesis is the easiest way to do this.

measure your aluminum oxide, magnesium oxide and sio2 in the correct molar ratio.

then mix together by hand and put into an al2o3 crucible (platinum if you want exact ratios) do not pack into crucible for easy removal. fire at approx. 1450C for about 50hrs. let cool and remove from crucible. mortar and pestle back to a find powder and put back into crucible and do again.

xray for confirmation but you should be done after twice cooked.

if you are looking for something with lots of surface area (more reactive) you will need to do something a bit different using nitrates mixed with citric acid. this method will char and create your powder via pyrolysis method.

I can give you a recipe that I have used for other oxide powders that works well. contact me at my email address.