Using natural stone decor well: bowls, vases, objects

Few pieces, but visible ones

Two to three stone objects per room are enough. Not to be sparing, but because each individual piece brings its own pattern. Five objects in five different stones do not add up to a collection but to visual clutter.

If you want more, stick to the same material. Three travertine pieces in different shapes look as if they belong together, because colour and texture come from the same family. The same applies to marble, limestone or onyx: one material, several shapes – that reads as a group. Several materials side by side look random.

Group in odd numbers, usually in threes, with different heights and a common point of reference – a tray, the edge of a table, an axis to the wall. Anyone who instead spreads each piece individually across a surface gets three small focal points instead of one large one.

Stone needs contrast, not company

A stone object comes into its own when there is calm around it. On an empty wooden sideboard, in front of a plain wall, on a dark coffee table.

Next to strongly patterned textiles, in front of wallpaper or among many small decorative objects, the pattern of the stone gets lost – and with it the reason for putting it there at all.

The most reliable neighbours are matt and plain: wood, linen, wool, ceramics without pattern. The surface underneath counts too: on a strongly grained wooden top, two patterns compete with each other; on a calm surface, only one remains.

Light is the second lever. Light falling from the side traces pores, veins and edges; frontal light flattens them. A piece that looks lively by the window during the day can look dull under a ceiling spotlight – and vice versa.

Hardness determines how it is handled

Its Mohs hardness tells you how delicate a stone object is. The scale runs from 1 for talc to 10 for diamond and indicates which material can scratch which.

Selenite, a variety of gypsum, sits at Mohs hardness 2. It can be scratched with a fingernail and is water-soluble – moisture attacks the surface, which becomes dull and rough. Such pieces are only ever dusted dry.

Limestone and travertine, which geologically is also a limestone, sit at around 3. They are sensitive to scratches and above all to acid: lemon juice, vinegar, wine or acidic cleaners dissolve the lime and leave matt marks that cannot be wiped away. Marble behaves similarly and falls within the same range.

Stones containing quartz are considerably more robust. Agate sits at 6.5 to 7 and is therefore hard enough that ordinary metal leaves no marks. Granite falls within a similar range.

As a rule of thumb: anything below hardness 4 should be treated like a lacquered furniture surface, anything from 6 upwards copes with normal everyday life. This one number explains most of the care instructions that come with stone objects.

Plan for the weight

Stone objects are heavier than their size suggests, and that has practical consequences.

As a guide: depending on the type, natural stone weighs about 2.3–2.8 kg (5.07–6.17 lb) per litre, so roughly two and a half times as much as water. A stone bowl 25 cm (9.8 in) in diameter can therefore easily weigh four to five kilograms (8.82–11.02 lb), a compact palm-sized bookend a good two kilograms (4.41 lb), and a set of three small stands together likewise several kilograms.

Weights like these do not belong on thin shelves, on narrow consoles or on glass tops without a stated load capacity. A shelf of 16 mm (0.6 in) chipboard with a span of 80 cm (31.5 in) can only hold a few kilograms in the long term before it visibly bends. This deformation develops gradually over months and does not recover when the load is taken off again. Solid wood and metal can bear more; glass depends on thickness and supports – the manufacturer's load rating is not a formality here.

Anyone placing a stone object on a delicate wooden piece of furniture is better off putting felt underneath. Rough stone edges leave marks as soon as the piece is moved even once, and with open-pored stone, felt also keeps moisture away from the furniture surface.

The footprint counts too. Tall, narrow objects have a high centre of gravity and tip over more easily than their weight would suggest. In areas people walk through, on narrow consoles or in households with children and pets, this is not a theoretical risk: a falling stone object usually damages both the floor and itself.

What belongs in a stone bowl

Little. A stone bowl is already an object in itself and needs no contents to make an impression.

If you do want to put something in it: things that are softer than the stone. With a bowl of selenite this is not a question of style but of protecting the material – at Mohs hardness 2, keys and coins leave marks immediately. With limestone and travertine, sensitivity to scratching is lower; there, acidic liquids are the bigger problem. With agate or granite, keys and coins are fine.

Cut citrus fruit, dripping candles without a coaster and damp plant material do not belong in any stone bowl. Oil, wax and fruit acid soak into open-pored stone, and once soaked in, they can hardly be removed from the surface.

Natural stone is not watertight

Limestone, travertine and sandstone are open-pored. Travertine's pores are even visible; when it is cut to size, they are partly filled and partly left open. Water penetrates these pores, spreads through the stone and often only emerges again on the underside hours later, without anything having been visible on the surface.

For vases, this means: without an internal seal or insert, a vessel made of natural stone is not a container for water but for dry arrangements – dried flowers, grasses, branches. For cut flowers, place a glass or a test tube inside and uses the stone as a sleeve. That is not a makeshift solution but the usual way stone vases are built.

The same applies to saucers under house plants. A stone planter needs a watertight insert, otherwise water travels through the stone into the furniture surface below. And standing water on light limestone leaves rings over time that stay darker than the rest of the surface.

Create height rather than fill surfaces

The most common mistake with decoration is that everything stands on one level. Stone is particularly well suited to breaking this up, because it is stable enough to serve as a plinth.

A low stand under a candle, a bookend holding a book upright, a bowl on a pedestal – this turns two objects at the same height into a group with staggered levels.

For the staggering to be read as intentional, the heights must differ clearly. A ratio of about one to one and a half to two has proved its worth: one low piece, one one and a half times as tall and one twice as tall make a clean gradation. Three objects of almost the same height, by contrast, look like an oversight.

The tallest piece usually stands at the back or on the outside, not in the middle, so that the group leads the eye in one direction. And the gaps stay small: objects that touch or almost touch each other read as a unit; those pulled far apart read as a row.

Cleaning and care

Natural stone needs little care, but that little should be done consistently. Dust is removed dry with a soft cloth. For heavier soiling on less sensitive stones, a slightly damp cloth with clear water is enough; afterwards it is wiped dry.

Vinegar, lemon and limescale cleaners are unsuitable, as are scouring agents and abrasive sponges. On stones containing lime, acids attack the surface chemically; on soft stones, scouring agents scratch it mechanically. Water-soluble stones such as selenite tolerate no moisture at all and are only dusted.

Blot stains immediately, dabbing rather than wiping – wiping only spreads the liquid over a larger area and pushes it deeper into the pores.

For porous stones in everyday use, there are impregnating sealers. They do not close the pores completely, but they delay the penetration of liquid and so buy time to wipe it up. They are no substitute for a coaster, and the treatment has to be repeated as well.