The Colour That Was Never Meant to Exist
Purple sea glass starts life as clear glass. That’s the thing most people don’t know, and it’s what makes finding a piece feel like a small act of time travel.
Between roughly 1880 and 1914, glassmakers added manganese dioxide to their batches as a decolorant; it neutralised the natural green tint that iron impurities gave to glass, producing the clear bottles and jars that Victorian households wanted. It worked perfectly. Until the sun got involved.
Given enough UV exposure over enough decades, that manganese slowly oxidises, and the glass shifts colour from clear to the faintest blush, deepening over time to lavender, then soft amethyst, then, in rare cases, a genuine purple. The longer the exposure, the deeper the colour. A pale lavender piece might have spent forty years on a south-facing beach. A deep violet piece has been sitting in sunlight for over a century.
You didn’t find a purple bottle. You found a clear bottle that the sun turned purple. That’s a different thing entirely.
Best UK beach for purple sea glass right now
Robin Hood’s Bay, Yorkshire, is the pick for purple and lavender. The village’s history of tipping domestic waste over the cliffs throughout the Victorian and Edwardian era means clear manganese glass entered the sea here in quantity, and the North Sea has had over a century to tumble it and the sun to work on it. Well-frosted lavender pieces turn up with more regularity here than almost anywhere else on the Yorkshire coast.
Check conditions before you go:
Other UK beaches where purple has been recorded
- Seaham, County Durham — purple and amethyst recorded among rare finds
- Boulmer, Northumberland — occasional lavender among the rarer colour finds
- Pentewan, Cornwall — sun-purpled glass recorded; the south-facing aspect helps UV exposure
- Walton-on-the-Naze, Essex — Victorian domestic glass from the eroding Naze cliffs includes manganese glass
Below is different from the map above, as this is the best place to find Lavender seaglass when conditions are perfect in the UK
What to look for
Pale lavender is easy to miss; it can look almost white in dull light or when the glass is dry. The tell is a faint warmth in the colour, a blush quality that pure frosted white doesn’t have. In sunlight, it’s much more obvious: hold a piece up to the light and the lavender glow is unmistakable.
Deeper purple pieces are rarer and easier to spot. If you find something in that range, it’s been in the sun for a very long time. Check the thickness, thicker glass tends to show the colour more richly than thinner shards.
Both lavender and purple are worth picking up immediately. They’re more commonly found than red or orange, but still rare enough that leaving one behind is always a mistake.
You can check out our interactive seaglass map, where you can filter by colour and find the nearest purple seaglass beach near you
From beach to jewellery
Lavender and purple sea glass set beautifully in silver, that soft amethyst tone against metal is one of the most elegant combinations in the collection. Browse the current pieces at Mermaid Tears, each one hand-hunted from a UK beach and handmade to order.
Conditions change daily. Always check tide times before visiting.