Raw collectible minerals, natural stones sold individually or in bags — LITHOS

Yes, for 19 of the 20 materials offered: tourmalines, quartz, amethysts, corundum, apatite, lapis lazuli, agate, obsidian, sunstone, malachite, optical calcite, pyrite, kyanite, shungite, and yooperlite are raw natural stones, not polished. The only exception is opalite: despite its name, it is a man-made opalescent glass, appreciated for its bluish reflections against a dark background and orange ones when backlit. We prefer to state this clearly, as many sellers present it as a stone. It remains interesting in an educational collection, precisely for learning how to distinguish a natural mineral from a synthetic material.

The 1 piece format corresponds to a single raw specimen, ideal for completing a collection or testing a mineral. The 50g bag and 100g bag formats contain several fragments of the same mineral, for a total weight of approximately 45 to 55g or 95 to 105g. The number of stones in a bag depends on their size, which varies from one harvest to another: it is therefore not fixed. Bags are well-suited for comparing several samples, putting together a decorative dish, sharing stones between children during a workshop, or filling a display case.

The exact size of an individual specimen is not provided by our supplier and varies from one mineral to another: an amethyst point, a small agate geode, and a kyanite blade obviously do not have the same size. These are raw natural stones, each unique in its shape, shade, and dimensions. The photos give an idea of the general appearance, but the piece received may differ slightly. If you are looking for a specific size for a decoration project or display case, do not hesitate to ask our customer service team before placing your order: we will let you know what we can verify.

The Mohs scale, proposed in 1812 by mineralogist Friedrich Mohs, classifies minerals according to their resistance to scratching, from 1 (talc) to 10 (diamond). A mineral scratches all those that have a hardness lower than its own. It is a relative and non-proportional scale: the gap between corundum (9) and diamond (10) is much larger than between talc (1) and gypsum (2). Several LITHOS stones are among the ten reference minerals: calcite (3), apatite (5), quartz (7), and corundum (9). You can therefore perform simple scratch tests at home.

Optical calcite, also called Iceland spar, is a very transparent calcite that exhibits strong birefringence: a light ray passing through it is split into two rays that do not propagate at the same speed and do not follow the same path. The result: a line of text placed under the crystal appears doubled. If you rotate the stone, one of the two images rotates around the other. This phenomenon, described as early as the 17th century, played an important role in understanding the nature of light. It is one of the most spectacular experiments to perform with this collection.

No, no UV lamp is included. Yooperlite is a grey rock with a discreet appearance in daylight; under a long-wave (365 nm) ultraviolet lamp, the sodalite grains it contains become fluorescent and form bright yellow-orange spots and veins. The effect is more intense in a dark room. A small 365 nm UV flashlight is generally sufficient. Never look directly at the UV source and do not point it toward eyes. For a larger lot, a dedicated listing for yooperlite also exists in our Lab universe.

A simple soft brush or dry cloth is enough to dust them off. Avoid soaking them: some stones like malachite, calcite, or pyrite do not tolerate water, household products, or prolonged humidity well, and pyrite can tarnish in humid air. Store soft stones (calcite, malachite) separately from hard stones (quartz, corundum, tourmaline) to avoid scratches. A compartmented box, with a small label for each mineral, remains the ideal solution. After handling malachite or pyrite, remember to wash your hands.