Green Crystals Guide: Mineralogy, Varieties & Jewellery

What "green crystal" means in BE.'s catalogue

"Green crystal" is a colour family, not a material. Across the wider market it can mean anything from emerald (a beryl) to jade (a jadeite or nephrite) to malachite (a copper carbonate) to a long list of dyed or coloured glass substitutes. BE.'s catalogue narrows the term deliberately. The brand works with green stones that are quartz-family or related silicate materials, sourced with country- and region-level documentation (and specific deposit information where the upstream supplier has disclosed it), with full treatment disclosure, and graded against the in-house 4T system. Inside that scope there are three materials, and this guide is about those three.

The three greens BE. works with

Prehnite — pale green calcium aluminium silicate

Prehnite is a calcium aluminium silicate with the formula Ca₂Al(AlSi₃O₁₀)(OH)₂, sitting at 6 to 6.5 on the Mohs scale. It forms in low-temperature hydrothermal cavities in basalts and metamorphosed mafic rocks, and at gem grade it produces translucent, waxy beads in pale yellow-green to mid-green. BE.'s prehnite work draws on Mali, Australia, and Cape South Africa, with country and region recorded on each Stone Origin Card; where the upstream supplier has disclosed a specific locality, that is listed too. The material's defining visual is its soft internal glow — light enters the bead and diffuses, rather than passing through cleanly as it would in clear quartz. Many prehnite beads also carry dark green epidote needles, which the 4T grading treats as a feature rather than a flaw when they are well distributed.

Green phantom quartz — clear quartz with chlorite phantoms

Green phantom quartz is clear quartz (SiO₂) that grew in stages, with thin layers of green chlorite minerals deposited on the crystal surface between growth phases. When growth resumed, the chlorite was sealed inside, forming a "phantom" — a ghost of the earlier, smaller crystal frozen inside the larger one. At Mohs 7 the host material is transparent; the phantom inside is what carries the colour. BE.'s green phantom strands draw on Brazilian and Madagascan deposits and read as transparent beads with internal landscapes of green chlorite — pale to medium green, often with multiple visible layers in a single bead.

Emerald phantom quartz — clear quartz with deep green chlorite phantoms

Emerald phantom quartz is the same structural phenomenon as green phantom quartz, but with chlorite material rich enough in chromium and vanadium to produce a deep, saturated emerald-green inclusion. The host is clear quartz at Mohs 7; the phantom inside is darker, more concentrated, and visually closer to true emerald in tone. The material is genuinely rarer than green phantom quartz — the chlorite chemistry that produces emerald-grade saturation occurs in a narrower set of deposits. BE.'s emerald phantom work is sourced from Brazilian and Namibian localities and treated as Heritage-tier material when the phantom is well-formed and the host quartz is clean.

What separates them — a material comparison

How to choose between them

The choice between the three usually comes down to three preference questions. None of them has a right answer — they sort buyers toward the material that will sit best with them on the wrist.

• Do you want a uniform colour or an internal landscape? Prehnite gives a uniform pale-green field across all beads. Both phantom quartzes give a transparent bead with a green landscape suspended inside, and the landscape is different in every bead.
• Do you want a soft tone or a saturated tone? Prehnite and green phantom quartz both read as pale to medium green. Emerald phantom is the saturated option, closer to true emerald in tone.
• How much wrist presence do you want? Prehnite reads as the most discreet of the three at the same bead size, because the colour is softer and the material is translucent rather than transparent. The two phantom quartzes read as more architectural, because the eye reads through the clear host into a defined internal structure.

What BE. selects for in each

The 4T grading framework asks slightly different questions for each material.

• Prehnite — Transparency reads as translucency. Tone is judged on the evenness of the yellow-green colour across beads. Texture penalises pits and surface dullness, and the distribution of epidote needles is read on the Tone axis when they are present. Treasure scores higher for the better-documented African deposits.
• Green phantom quartz — Transparency is judged on the clarity of the host quartz, separately from the colour of the phantom. Tone covers the saturation and definition of the green phantom layers. Texture is the most demanding axis here, because internal fractures break the phantom's continuity. Treasure scores higher for the most consistent Brazilian and Madagascan sources.
• Emerald phantom quartz — The phantom's saturation and the cleanliness of its boundary against the host quartz are the defining material questions. Heritage-tier emerald phantom requires both: deep, even saturation in the phantom and a clean, undisturbed host crystal around it.

How to wear green strands with other BE. series

Green is one of the colours that sits easily across BE.'s four series. Prehnite pairs cleanly with the softer translucent strands — clear quartz, rose quartz, moonstone — because the optical character is similar: all read as soft internal glow. The two phantom quartzes pair more naturally with other inclusion-bearing materials — rutilated quartz, hematoid quartz, super seven — because the eye is already trained to read internal landscapes when those strands are worn together. A common layered combination is one prehnite strand with one green phantom strand, which produces two different greens at two different optical depths on the same wrist.

Caring for green crystal jewellery

All three materials sit at Mohs 6 to 7 and tolerate normal daily wear, with three practical notes. Prehnite is the softest of the three and the most prone to surface dulling — it benefits from a soft dry cloth wipe after wear and from being stored away from harder stones. Both phantom quartzes are fully water-safe and resistant to most household chemicals, but neither should be left in prolonged direct sunlight, since some chlorite inclusions can shift in tone over years of UV exposure. None of the three should be cleaned with ultrasonic cleaners or steam cleaners — the thermal stress can propagate microfractures that were not visible before cleaning.

Where to start

For a first green strand from BE., prehnite is the gentlest entry point — the optical character is soft, the price is the lowest of the three, and the material reads well in most lighting. Green phantom quartz is the right choice for a buyer who wants a clear-host strand with internal landscapes. Emerald phantom quartz is the choice for a buyer who specifically wants the saturated emerald-green tone, and is comfortable that the material sits at a higher price point because it is genuinely scarcer.

Frequently asked questions

References

• The 4T grading system — the material framework BE. applies to every green strand.
• The Geological Codex — full material entries for prehnite, green phantom quartz, and emerald phantom quartz.
• Our Story — the geology-first position the catalogue is built from.
• The Strands collection — the complete BE. strand catalogue, including all green pieces.