What are glow stones?
Glow stones are irregularly broken pieces of stone, approx. 2 cm each, based on strontium aluminate, which store light and release it again in the dark. They need no electricity, cables or batteries. Each bag contains 300 g.
Which colour glows for how long?
Green and Blue-Green usually glow for more than 8 hours after a full charge, in complete darkness; tinted stones glow for a shorter time and more weakly.
| Colour | Effect | Afterglow duration |
|---|---|---|
| Green | base shade, glows most intensely | usually more than 8 h |
| Blue-Green | slightly cooler than green, also strong | usually more than 8 h |
| Yellow | yellow accent by day | up to 4 h |
| Brown | earthy accent, glows only faintly | up to 2 h |
| Blue | blue accent, glows blue | approx. 1 h |
All stones are at their strongest right after charging; the glow then gradually fades. If long glow matters most to you, choose Green or Blue-Green. Brown looks best between more strongly glowing colours.
How do you charge glow stones?
Glow stones charge with daylight or artificial light in a few seconds to minutes, fastest with UV light. This works as often as you like. Outdoors, place the stones where they get enough light during the day – in deep shade the glow stays faint.
How to use glow stones
Glow stones can lie loose or be worked permanently into resin and concrete.
- Loose as decoration: in garden gravel, flowerpots, planters, vases, rock beds or along paths.
- In resin: embedded in epoxy or casting resin, for example for bowls, tabletops or decorative objects.
- Concrete, terrazzo, steps: press into the still-wet surface and sand flush after curing. Alternatively, embed them in a transparent, walk-on layer of epoxy or exterior varnish.
Mixed into the concrete compound, the stones disappear. They only work where light reaches them – at the surface.
Glow stones or glow granules?
At approx. 2 cm each, glow stones are much larger than the 4 mm glow granules at 4–8 mm. The granules are the better choice when you want many small points of glow, for example in joints or thin resin layers. In the 4 mm granules the pigment is bound in synthetic resin, which makes them resistant to water – they are also suitable for vases.
Good to know
Glow stones are an aid for orientation and effects, not a light source. The glow becomes visible in real darkness, but barely under a streetlight. The stones are not a toy.
For finer grain sizes there are glow granules in 1 mm and 4 mm. Epoxy casting resin is suitable for embedding. Granules, Stones & Jelly gives an overview of all forms, and Afterglow explained covers the background.