In one paragraphAmethyst, citrine, smoky quartz, rose quartz, clear quartz, rutilated and hematoid quartz, the phantoms and Super Seven are not nine different stones — they are nine expressions of one mineral, quartz (SiO2, Mohs 7). What separates them is a single variable each: a trace element, an inclusion, or a dose of radiation. Learn the tree once and the whole confusing aisle of “crystals” collapses into a family you can read.
Walk past a crystal display and it looks like dozens of unrelated stones. Most of them are the same thing. Quartz is the second most abundant mineral in the Earth’s crust, and it is unusually willing to trap whatever is nearby as it grows. That openness is why one formula produces a violet stone, a golden one, a smoky one and a pink one — and why heating one variety can turn it into another.
Here is the family tree: nine quartz varieties, what each one shares, and the single trace that makes it distinct.
FIGURE: quartz-family-tree-varieties-guide-fig.png — branching tree from SiO2 to 9 quartz varieties with the trace that defines each, bold infographic style (image to be added)
One formula, one hardness
Every variety below is silicon dioxide in the same trigonal lattice, at Mohs 7, with no cleavage. That shared backbone is why they all wear similarly and take the same care. Quartz also splits into two structural branches: macrocrystalline (visible crystals — everything in this guide) and cryptocrystalline (microscopic crystals — agate, chalcedony, jasper). BE. works in the macrocrystalline branch.
The nine branches
| Variety | The one variable | Result |
|---|---|---|
| Clear Quartz | Nothing — pure SiO2 | Colourless, transparent; the baseline. |
| Amethyst | Iron + natural radiation | Violet colour centre. |
| Citrine | Iron, heat-shifted | Yellow to golden-orange. |
| Smoky Quartz | Aluminium + radiation | Grey, brown to near-black. |
| Rose Quartz | Microscopic borosilicate fibres | Soft, cloudy pink. |
| Rutilated Quartz | Rutile (TiO2) needles | Golden threads suspended inside. |
| Hematoid Quartz | Hematite (iron-oxide) inclusions | Red, rust and gold veils. |
| Phantom Quartz | Chlorite growth layers | Ghostly inner outlines (green phantoms). |
| Super Seven | Several minerals at once | A natural quartz blend in one stone. |
Two footnotes that resolve common confusion: blue needle quartz is clear quartz with dumortierite inclusions (another inclusion branch), and prasiolite (“green amethyst”) is heat-altered amethyst — a colour-centre branch, not a separate species.
Reading the tree
- Colour centres vs inclusions. Amethyst, citrine and smoky get colour from the lattice itself; rutilated, hematoid and phantom quartz get it from trapped minerals.
- Heat moves between branches. Heating amethyst makes citrine or prasiolite — same atoms, different conditions.
- Clarity tells the type. Lattice-coloured quartz is usually transparent; inclusion stones carry visible internal structure; rose quartz is cloudy.
- Hardness is constant. All sit at Mohs 7, so any quartz bracelet shares the same durability baseline.
- Names are branches, not trees. “Fire quartz” or “Venus hair” are leaves on the hematoid and rutilated branches.
Trade names, decoded
- “Green amethyst.” Prasiolite — heat-altered amethyst, still quartz.
- “Fire quartz.” Hematoid quartz — iron-oxide inclusions.
- “Venus hair / angel hair.” Fine rutilated quartz.
- “Smoky topaz.” A misnomer — it is smoky quartz, not topaz.
- “Cherry quartz.” Usually manufactured glass, not a quartz variety at all.
How BE. grades quartz
Across every branch, BE. reads each strand against the Crystal 4T framework — Transparency, Tone, Texture, Treasure — and records the variety, the colour mechanism and the source on a Stone Origin Card. The family tree is the map; the card is the specific coordinate for your stone.
Frequently asked questions
Q1.Are amethyst and citrine the same mineral?
Yes — both are quartz (SiO2). Amethyst is violet from iron and radiation; heating it shifts the colour centre to citrine’s yellow-orange. Most commercial citrine is heated amethyst.
Q2.Macrocrystalline vs cryptocrystalline quartz?
Macrocrystalline has visible crystals (amethyst, citrine, clear). Cryptocrystalline (agate, chalcedony, jasper) is microscopic crystals packed together. Both are SiO2.
Q3.Why are there so many quartz varieties?
Quartz is abundant and readily traps trace elements, inclusions and radiation as it grows, each producing a different colour or effect from one formula.
Q4.Is rose quartz coloured by iron?
Not mainly. Its pink comes largely from microscopic borosilicate fibres dispersed through the crystal, which is why rose quartz is usually cloudy rather than transparent.
Q5.Do all quartz varieties have the same hardness?
Essentially yes — all macrocrystalline quartz is Mohs 7, so they share scratch resistance and care. Inclusions can create local weak points, but the host hardness is constant.
Q6.Is Super Seven really seven minerals?
It is quartz naturally containing several minerals, traditionally said to be seven. The mix varies, so the name describes a quartz-based blend rather than a fixed recipe.
References
- Quartz — Wikipedia
- Quartz Description — GIA
- Quartz — Mindat.org
- Rossman, G. R. (1994). Colored Varieties of the Silica Minerals, Reviews in Mineralogy 29.
- Deer, Howie & Zussman (2013). An Introduction to the Rock-Forming Minerals, 3rd ed.
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