Describe a pebble without guessing its origin

Write down size, shape, surface roughness and any visible bands or grains. Use a ruler or reference object in a photograph and note how the colour changes when wet.

Photograph a rounded pebble with a pale stripe against a millimetre scale. Notice whether the irregular cases cluster around a time, a particular part of the site or a change in observation method. A bright photo taken at an angle can reveal a marking that was always there. A different viewpoint can equally hide one you had seen on every earlier visit.

Wetting the surface may make the stripe clearer and reveal grains difficult to see when dry. End the entry with the strongest description you can support and the thing you would like to see on a future visit. If somebody else joins you, show them the starting viewpoint and write down what each of you noticed independently. Different observations may reveal where the record needs another angle or a clearer description.

Record where you observed the pebble and its surroundings. A riverbank or footpath label is stronger evidence than an unsupported story about how the pebble arrived there.

A bright line can look like a separate layer when it is actually light reflected in a scratch. A photograph can preserve an apparent colour shift while overlooking the surface that caused it. Inspect a shaded as well as an exposed part, and keep a wide image whenever colour might be influenced by a neighbouring wall, water or foliage. A rough sketch of the positions can establish that relationship even when the photograph is dark.

Take a second dry picture from an angle that lets you inspect the stripe's position. Start with enough detail to recognise the same part of the site without relying on memory. Draw a landmark fixed outside the feature you are following. A straight branch can bend or disappear, but the corner of a wall or the distance from a path junction can still identify the intended observation area.

Include the surrounding stones in a wide setting photograph before considering an origin. Keep absence, uncertainty and poor visibility in separate fields. Those distinctions become important when you turn a notebook into a seasonal summary. A missed visit cannot establish whether a change happened earlier or later, but two positive sightings can set helpful limits around when it was possible.

Give an observation room to stay unresolved. A sketch, a time and a place can be worth keeping even when the exact name or cause is unclear. Repeated visits may close one gap and open another. When they do, use a note beside the original date so it remains possible to see how your reading changed. If you share the record, choose a photograph that shows the most informative feature you can safely see and one with wider context. Add the season, general habitat and what remained outside the frame. For a recurring observation, keep the same short fields and compare the records on their own before looking at possible explanations. Compare a flat face with a newly exposed edge in a separate sample rather than scratching a stone you intend to preserve. Separate what was visible from the explanation it suggests. A label such as three open tips on the higher branch can be checked later. A statement that a warmer position caused the earlier change needs repeated observations, comparable conditions and some care about what else differs between the two places.

Use photographs where collection rules are uncertain and study patterns in several specimens before naming a rock. Observe the edge of the setting as well as its centre. The ground beyond a branch, shell or bank mark may hold a useful reference for distance or scale. A picture cropped close to the subject is valuable for comparison, while a second frame can reveal an environmental cue affecting its appearance.