Marte ring in silver with rectangular green jasper plate and bronze corner

How it is made

The words of the trade, one by one, explained to those who do not know them.

01

Irregular voids

In geometric piercing the error is measured against the module that repeats; here there is no module, and every void has to be decided as it is opened. The risk shifts: not that a mesh comes out crooked, but that at some point the solid is left too thin, and the piece gives way exactly there. Whoever does it holds together two things that pull in opposite directions, an outline that has to look random and a thickness that has to carry.

02

Oxidizing

The silver is darkened on purpose, and then re-polished only where the light has to come back. The black stays in the voids and the recesses, the bright on the raised areas: it is a design made by subtraction, and whoever does it decides where to stop the cloth.

03

Table cut

The stone has no crown and no facets: it is sawn into a flat slab and polished on the face in view. There is no light to send back, there is only the color and what the mineral has inside it, so the slab has to be taken where the veining holds: a plane crooked to the layers makes a corner break off under the wheel, and on a stone already sawn there is no recovering it.

04

Ball-tipped claws

They are not pointed prongs: they are four round-headed silver grips, one at each corner, pushed over the edge of the stone so as to hold it by bearing flat rather than by digging in. On a slab with a sharp edge it is the only choice, because a narrow point on a corner of quartz chips it, and a chip on a polished plane shows from every side. The difficulty is that all four have to press the same: one tighter tilts the slab and leaves the others in the air, one looser lets it turn in its seat, and to correct one you have to go back with the tool over a stone that is already mounted.

05

Bronze and silver on the same piece

Bronze is copper with some tin, and under the flame the copper oxidizes before anything else: it covers itself with a black scale which, if it stays shut inside the joint, means the solder does not hold. It also melts higher than silver at nine hundred and twenty-five thousandths, so the part at risk is always the silver — it is heated just enough to take on the bronze, and a second too long sinks the metal underneath. Then the two age differently, the silver towards gray and the bronze towards brown: the contrast you see today is a starting point, not a fixed state.

06

Green jasper

Jasper is chalcedony: quartz grown in fibers so tight that the single crystal cannot be made out. What separates it from the other varieties is how much foreign matter it has inside — up to a fifth of its weight in iron oxides and clay — and it is exactly that matter that makes it opaque and gives it its color. The green comes from iron silicates scattered through the mass and is never laid evenly: it arranges itself in areas, veils and veins, and on green jasper red points of iron oxide often appear. That is why it is not faceted. The light does not pass through it, there is nothing to send back, and a crown of facets would add nothing: it is sawn flat, polished, and what you look at is the pattern the rock has inside. At the seventh degree of hardness it takes everyday wear better than almost any colored stone; the risk comes earlier, in the cutting, because a vein of clay or a closed fracture cannot be seen from outside and breaks under the wheel, and a slab already sawn cannot be recovered.