Will these still work as quartz does because of the shape? Or do I really need real quartz?
So it's entirely different to quartz if it's glass, however, glass can be crystallized (see below).
I came across
this excellent answer to the question on Quora, "Why is glass not a crystal?"
Glass is usually not a crystal. But glass can also be made by a net of crystals. The differentiation will appear in the processing of the materials.
Glass can not be classified as a crystal when it is in its amorphous phase. That means that the silicon dioxide will not be organized at long molecular ranges. It will be a mess. A random mess, thus amorphous. That is the glass we usually make windows and glasses out of.
The definition of a crystal states that a crystal is a solid material whose atoms or molecules are ordered in a highly arranged microscopic structure.
However, given the right conditions and the correct additives, glass can be crystallized. That means that the molecules that compose glass itself will be aligned and organized at long molecular ranges. This means that the structure of the glass won't be a mess anymore, assuring some better properties, such as higher mechanical resistance, more precisely its Yield Modulus. And this way the glass is also going to break into little pieces, like we see in bathrooms.
And this is good info here:
"Glass is not a crystal. Like quartz, glass is composed of silicon dioxide, and both materials are clear in their purest state. The difference is in the way they form. Quartz forms very gradually, aligning its molecules one by one into a perfect crystal lattice. In contrast, glass forms when the silicon is heated and quickly cooled, either by the earth or by man. The quickly cooled molecules have no time to form a lattice, and instead solidify with no particular pattern.
So the question sometimes comes up: Since crystal healing works by aligning the perfect structure of crystals with the energy field of the human body, does glass even
have metaphysical properties? What, if anything, are the various forms of glass good for?" (
https://mimosaspirit.com/glass-has-properties-too/)
And like Lila touched on, natural forms of glass are different again and have various properties.