Sukabumi Green Stone for Swimming Pools
The stone that turns pool water emerald is not doing anything mysterious — it is simply coloured all the way through. Here is how to specify it properly, and where it goes wrong.
If you have seen a photograph of a pool in Bali where the water is an impossible emerald green, you have seen Sukabumi green stone. It is the single most requested Indonesian stone in international pool architecture, and it is also the one most often specified incorrectly.
Why the water turns green
There is no trick to it. The stone is a fine-grained volcanic material whose mineral colour is green throughout. Underwater, you are looking at that colour through a water column, so it deepens with depth: shallow steps read soft sage, a two-metre deep end reads full emerald.
Because the colour is the material rather than a coating, there is nothing to fade, craze or delaminate. Glazed ceramic pool tiles achieve a green by applying colour to a surface; that surface is the thing that eventually crazes under thermal cycling and pool chemistry. Pools tiled in Sukabumi green thirty years ago read the same today.
What to specify
Thickness
10–15 mm below the waterline on walls and floors. 30–40 mm for coping, steps and any edge that takes load or impact. Specifying 10 mm coping because it matched the tile price is the most common and most expensive mistake on this material.
Finish
Honed on submerged walls and floors — it gives the cleanest colour reading and is comfortable against skin. Bush hammered on steps, benches, the swim-up bar shelf, coping and any barefoot surface. The finish decision is about grip, not appearance, and it should be made position by position rather than for the whole pool.
Format
100 × 100 through 300 × 600 mm are all standard. Smaller modules handle curved walls and level changes with fewer cuts; larger modules are faster to install on flat surfaces and give fewer grout lines. For a curved or freeform pool, 100 × 100 or 150 × 150 mm is usually the practical answer.
Order tile, waterline and coping together
These three elements must come from the same material batch. Natural stone varies between quarry blocks, and a coping ordered three months after the tile will not match — the step in tone will be visible exactly where the eye lands, at the edge of the water.
This is the single most common failure on pool projects, and it is entirely avoidable. Send the pool drawing at enquiry stage and order everything in one production run.
Salt water, chlorine and sealing
Sukabumi green works in both chlorinated and salt-water systems and is used extensively in both. For salt-water pools we recommend a breathable penetrating sealer — not a film-forming one, which will eventually lift under hydrostatic pressure from behind.
Normal pool-water chemistry management is all that is required thereafter. Avoid strong acid cleaners: they etch most natural stone, and there is no need for them on a properly maintained pool.
Calculating quantities
- Tile: total wetted area (floor plus all four walls plus steps and benches) plus 10% for cuts, or 15% on a freeform or heavily stepped pool.
- Waterline course: pool perimeter × the course height, usually specified as a distinct band.
- Coping: pool perimeter in linear metres, plus corner pieces counted individually.
- Any spa, plunge pool or water feature intended to match — add it to the same order.
Send us the pool drawing and we produce this take-off with the quotation rather than leaving you to estimate it. It takes us an hour and it removes the most common source of a short shipment.
Where it goes wrong
- Coping ordered separately, later, from a different batch. The tone steps at the water edge.
- Coping specified too thin. It chips at the edge within a season of use.
- Honed finish used on steps. Slippery underfoot, and a liability issue on a commercial pool.
- Film-forming sealer applied. It lifts under hydrostatic pressure and looks worse than no sealer at all.
- Waterproofing membrane treated as optional because the stone is dense. Stone is a finish, not a waterproofing layer.
- Ordering only the measured area with no waste allowance, then discovering the shortfall mid-installation.
What it costs to get right
Nothing extra, in most cases. Every item on that list is a specification decision rather than a budget one. Ordering coping in the same shipment costs the same as ordering it later. Specifying bush hammered on the steps costs the same as honed. The expensive version of this material is the one where these decisions were made by default rather than deliberately.
