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Gold on quartz


#1

Can anyone point me to techniques for plating or adhering a gold
coating to the ‘back’ of a polished quartz slab so that, like a
mirror, it can be seen through the ‘front’? Thanks in advance,

Dan


#2
  Can anyone point me to techniques for plating or adhering a gold
coating to the 'back' of a polished quartz slab so that, like a
mirror, it can be seen through the 'front'? 

You can use a gold-colored foil or ribbon or mylar (all from a gift
or craft store) and adhere with any clear glue – epoxy or even
superglue. I sometimes use this method for cabochons that will be
bezel set, i.e., the backs will be protected and invisible.
Depending on how you plan to use your quartz slab, this method may or
may not be suitable.

Beth


#3

Vacuum deposit or “sputter” it on. This is the method used to put
reflective coating on optical mirrors. Gold coatings are used for
the high Infra red reflectivity. Where to get it done will depend
largely upon where you are. Check the Amateur telescope makers
sites. Gold is regularly deposited on optical quartz. Jesse


#4
    Can anyone point me to techniques for plating or adhering a
gold coating to the 'back' of a polished quartz slab so that, like
a mirror, it can be seen through the 'front'? Thanks in advance, 

G’day; One method is called sputtering, and another is metal
evaporation - which gives the best effect. This is done in a very
high vacuum and tiny pieces of gold or any metal are placed in either
a coil of fairly heavy gauge tungsten or molybdenum wire, or a hollow
in a little piece of sheet, which is electrically heated to a white
heat, and the gold literally boils off. It’s vapour travels in
straight lines because there are very few air molecules for it to
bounce off. It is usually done in a heavy glass bell jar and the
entire interior of the jar becomes coated with the metal, gold,
silver, copper, as you wish. The object to be coated, be it quartz
or glass must be scrupulously, chemically clean.

I had to gold coat a large quartz prism (face about 2 inches by 3
inches) and also a series of glass concave lenses for an infra red
instrument I was building, plus a prism of pure salt crystal (it
looked just like the quartz one). I even had to build the high
vacuum evaporation device, for this was in 1948 just after the war,
when it was a case of ‘make it yourself or forget it’ for research
equipment.

Silver can be coated on glass chemically, (which I have done) and I
think it might be possible to do that with gold but have never done
it.

There are doubtless firms who will do this for you; coated lenses
and prisms are used in the photographic industry and in research
institutions.

Try asking Google for metal evaporation coatings or for sputtering

– Cheers for now,

John Burgess; @John_Burgess2 of Mapua Nelson NZ


#5

Here is a good source for vacuum deposition of metals :

http://www.clausing.com/

Jesse


#6

If you know anyone who uses a scanning electron microscope (research
lab, university), ask about their coating apparatus. Many
non-conductive specimens must be prepared with an
electrically-conductive coating, and that coating is frequently gold
deposited in a vacuum from a plasma. Not that they can just coat
your specimens for free, but often there is extra room in the
coater, and they might be able to put a few small items in and run
them through several cycles along with legitimate specimens. Each
cycle will deposit another layer, so it’s best if you can be present
to say when it’s enough. Also, specimens must often be rotated or
turned between cycles to achieve an all-over coating.

Tas