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[Iacopo]

I found some nice malachite balls, so I bought them, with the aim to make a couple of spinning tops out of them.
I will expose here the process of the making, step by step.

I start by drawing the top.  I make some sketches trying to figure out what shape could be best.
I decide what materials could be used; in this case I decided to use ebony for the wooden parts, because the malachite balls have some almost black areas and I feel that ebony will look nice with this malachite.
At some point I found some phosphorescent glass green balls for sale, from China, I thought that they could look cool in the stems, so I included the phosphorescent ball in the design, and ordered them.   



When I have clear ideas enough, I make a more accurate drawing, with the definitive proportions and dimensions.
In the beginning I wanted a simpler profile, (at the top left, and the large top in the middle, drawing below), then I thought that it would look better making it a bit more decorative, so I drew again some details; the stem, (at the top right), the stand ring, (on the bottom left), and the pedestal for the malachite ball, (on the bottom right).

The large ball of the base will be of malachite.  The core of the top, (the central part holding together the flywheel, the stem and the tip), will be made of malachite. Brass flywheel. Ebony stem, (with an ergal-hss frame inside for more stiffness and robustness), ebony stand ring, ebony pedestal for the malachite ball.

[Iacopo]

I will make two tops with this design.
I prepared the pieces for making them;
I cut the ebony pieces...



I roughly made them circular with the bench grinder.



I glued temporarily some of these ebony pieces to discs. These discs can be attached to the lathe and allow for the glued ebony pieces to be turned and machined at the sides, which would be not possible if the ebony pieces were hold directly by the jaws of the chuck.

[the Earl of Whirl]

Very interesting and amazing!!!  Thank you for sharing that.

[Iacopo]

Very interesting and amazing!!!  Thank you for sharing that.

You are welcome, Earl of Whirl.

[ta0]

Thanks for sharing this, Iacopo. It's treat to see the creative journey of a Master! 

[Iacopo]

Thanks for sharing this, Iacopo. It's treat to see the creative journey of a Master! 

Thank you, Jorge.  It's my pleasure to show the process of the making of these unusual tops.

[Iacopo]

I cut one of the malachite balls in two halves. They will become the cores of the two tops.
I used a simple hacksaw for the cut; first I put, (temporarily), a bit of epoxy resin and fiber glass around the ball, for to prevent chipping of the corners during the cut, (malachite is a bit brittle).
I flattened the cut surfaces with a diamond bench stone.



I turned the half ball on the lathe for to make a circular concavity in it, which is a joint for to glue it more safely to the backing attached to the chuck. 



I glued the half malachite ball with epoxy resin and I turned its sides with a straight profile, as a joint for the flywheel.



I holed the center of the malachite on the lathe with a diamond bit. The hole is for the stem holder.



The two tops, with the ergal stem holder and the brass flywheel, assembled at the left, and disassembled at the right.
These parts are glued together with epoxy resin.

[Iacopo]

The phosphorescent spheres that I ordered from China turned out to be of very poor quality; their phosphorescence is very weak and with a short duration.

I want those spheres in the stems, for three reasons: aesthetically, they recall the spherical shape of the malachite balls of the bases. They emit green light, green like the malachite, which is good aesthetically, to me. Then the phosphorescent spheres in the stems are useful for to balance the tops without having to use the paint and brush.

So I didn't give up, and I made my own phosphorescent spheres.

I turned a couple of plexiglass spheres, (12 mm), holed and empty inside:



Then I varnished their inside with very good quality phosphorescent powder, (from artnglow.com), mixed with transparent platinum silicone. 
Well, now I have the phosphorescent spheres.

[ortwin]

The phosphorescent spheres that I ordered from China turned out to be of very poor quality; their phosphorescence is very weak and with a short duration.
...

I have access to some phosphorescent spheres. But I do not have details about them in my head , and also it will be at least a week until I can find out more. Would it still be of interest for you?


Edit: found them on the internet. I think you can deal with the German text: [size=78%]https://www.moses-verlag.de/Leuchtende-Mondschein-Murmeln/038066[/size]

[Iacopo]

found them on the internet.

Thank you, Ortwin. They seem to have a nice texture, but they are too large, 25 mm.

For the two tops I am making, I am happy with my plexiglass spheres.
For the future, if it happens that you find little, (6-12 mm), phosphorescent balls, (or other shapes), I would like to know.

I ordered two kinds of phosphorescent balls, from two different sellers, both chinese, and they are both of poor quality.
I also found phosphorescent jade balls, but I think that they have weak phosphorescence.

[Iacopo]

I drilled an hole in the ergal stem holder.  This is for an hss rod, which will give more strength and stiffness to the upper part of the stem.



I glued a first little piece of ebony at the base of the stem holder.



After the resin has hardened, I turned that piece of ebony making the joint for the phosphorescent ball in it.



Now I could finish to assemble the top.
I glued in place the hss rod, (first photo below), the phosphorescent ball, (second photo), and the ebony cylinder of the stem, (third photo). 
Last, I glued three sticks for to stiffen the stem for the time necessary for to turn its upper part.



Now this top is ready for to be turned on the lathe.

[ta0]

So many steps, so much attention to detail . . .   

I was not expecting those temporary supports for turning the stem.

[Iacopo]

I was not expecting those temporary supports for turning the stem.

The stem is long and there is some risk to bend it a bit while turning its upper part, which would be very annoying.
Normally the tailstock and the dead center are used for to turn long items without risking to bend them, but for some reasons I have some difficulties using them in this situation, so I use the three glued sticks instead.

[Iacopo]

The assembly attached to the chuck, ready for the turning.



I start turning the upper part of the stem;



Some sanding...



I make the longitudinal grooves of the knurl;



Then I turn away the upper part of the three sticks, so I can turn the central part of the stem;

[Iacopo]

I continue turning the stem, following the design at the beginning of the thread;



Then I turn away some more of the three sticks, until they are no more attached to the stem;



At this point I remove them:



I turn the remaining part of the stem;



I use littler chisels for the details.
Ebony is solid and compact, and it is possible to shape tiny details out of it. 
It is also quite abrasive, and the chisels need to be resharpened often because they become repidly dull while turning ebony.



The stem is turned.  Next I will shape the malachite core.