11 · NovemberBlue Topaz Pendant 8 mm
Irradiated and then heated topaz. Two treatments, both listed separately.
- Natural
- Irradiated
- Heated
- Mohs
- Wear
- 8
- Occasional
£79incl. VAT
Section: November
November — Citrine and Topaz
Citrine — usually amethyst that has been through a kiln
Citrine at Mohs 7 is occasional wear. Topaz at Mohs 8 is still occasional wear, because of the cleavage — hardness and toughness are not the same property.
3 pieces in this month, ordered by how often they can sensibly be worn — the most forgiving first.
Mineralogy
Citrine is the yellow to orange variety of quartz, Mohs 7. Topaz is aluminium silicate fluoride hydroxide, Mohs 8, with one perfect basal cleavage that makes it far more fragile in wear than its hardness number suggests.
What the trade does to it
Most citrine sold anywhere in the world is heat-treated amethyst. Natural untreated citrine of good colour is genuinely uncommon. This site states it on every citrine piece rather than leaving it implied. Blue topaz is almost always irradiated and then heated; near-colourless topaz is the starting material. Both steps are declared here, separately.
Documented history
Citrine and topaz share November on the modern list. Commercial irradiation of topaz to produce blue began in the 1970s and is the reason blue topaz went from rare to inexpensive within a decade.
November pieces
From £79 · all prices include VAT
11 · November
Wear grades in this month
Suitable for daily wear
0 pieces in November
- Remove before contact sports and heavy manual work
- Remove before swimming pools and hot tubs — chlorine attacks the metal, not the stone
Occasional wear — avoid knocks
3 pieces in November
- Remove before gym equipment, gardening, DIY and washing up
- Do not stack against harder stones, which will abrade this one
- Avoid sudden temperature change
Delicate — special occasions only
0 pieces in November
- Remove before any physical activity — knocks will chip this stone
- Keep away from perfume, hairspray, cosmetics and hand sanitiser
- Avoid sudden temperature change and prolonged dry heat
- No ultrasonic tank, no steam, no soaking