======Copper Sulfate Crystals====== **Materials: **{{$demo.materials_description}}\\ **Difficulty: **{{$demo.difficulty_description}}\\ **Safety: **{{$demo.safety_description}}\\ \\ **Categories:** {{$demo.categories}} \\ **Alternative titles:** Growing Copper Sulfate Crystals ====Summary==== {{$demo.summary}} ====Procedure==== - Gather supplies: copper sulfate (CuSO4·5H2O) powder, very hot water, two clean glass jars with lids, a shallow dish, filter paper or coffee filter, nylon fishing line, a pencil or stick, spoon, and paper towels. - Prepare the growing solution: dissolve about 50–55 g copper sulfate per 100 mL very hot (not boiling) water while stirring until clear; let cool to room temperature. If cloudy, filter through paper into a clean jar. - Pre-equilibrate to exact saturation: sprinkle a pinch of copper sulfate powder into the jar, cover loosely, and leave overnight so excess solute crystallizes out and the remaining liquid is right at saturation. - Make seed crystals: pour a small portion of the saturated solution into a shallow dish and leave it undisturbed 1–2 days. Choose the most perfect, flat-faced crystal; handle with tweezers to avoid scratches. - Tie the seed: attach the seed gently to a thin nylon line (a tiny loop works well) and tie the other end to a pencil so the crystal can hang centered in a jar without touching sides or bottom. - Start growth: pour the pre-equilibrated saturated solution (from step 3) into a clean jar, suspend the seed in the center, and cover the jar partially to slow evaporation while still allowing a little air exchange. - Grow slowly: place the jar in a cool, vibration-free, shaded spot with stable temperature. Do not move or lift the crystal; check progress with a flashlight instead of removing it from solution. - Reduce competition: if small crystals appear on the jar bottom, quickly lift the seed out, decant the clear solution into a clean jar (leaving the small crystals behind), and return the seed. Keep this transfer under 1 minute. - Scale up carefully: after 2–3 weeks, give each growing crystal its own jar. If more solution is needed, prepare a fresh hot solution, cool, filter, pre-equilibrate with a pinch of powder overnight, then use. - Finish and dry: when the crystal is the desired size (often 3–6 weeks), remove it, place on paper to wick off solution, and air-dry. Do not rinse with water, which dulls edges. - Store to prevent dehydration: either coat the crystal evenly with clear nail polish, or seal it in a zipper bag inside a closed container with a little copper sulfate powder to maintain humidity. ====Links==== DIY Crystal at Home (2) - Copper(II) Sulfate - DIY bama: {{youtube>k3nClG-DT7w?}}\\ Growing A Beautiful Copper Sulfate Crystal! - Crystalverse: {{youtube>o813gUIIKjE?}}\\ 📄 The Best Way to Grow Big Copper Sulfate Crystals - Crystalverse: [[https://crystalverse.com/best-way-to-grow-copper-sulfate-crystals/]]\\ ====Variations==== * Grow a crystal cluster by starting from a slightly supersaturated solution in a wider jar and allowing faster evaporation. * Compare growth at different temperatures or with lids more or less closed to see how evaporation rate affects clarity and shape. * Try bottom-growth (no string) in a wide dish vs suspended growth on a line and compare faces and defects. ====Safety Precautions==== * Copper sulfate is harmful if swallowed and can irritate skin and eyes; wear gloves and safety glasses and keep chemicals away from food areas. * Supervise closely and keep solutions and crystals out of reach of young children and pets; label all containers “Do Not Eat.” * Use glass or plastic (not metal) containers; hot solutions can burn—handle heated water with care and place jars on stable surfaces. * Do not pour copper-containing solutions down the drain; save for reuse, allow to evaporate and store the recovered crystals, or follow local hazardous-waste guidance. * Wash hands after handling crystals or solutions; avoid creating or inhaling dust from dried crystals. ====Questions to Consider==== * Why is “grow it slowly” so important for single crystals? (Slow deposition lets ions add in order, reducing defects and giving flat faces.) * What happens if the solution is slightly undersaturated or slightly supersaturated? (Undersaturated dissolves the seed; too supersaturated causes rapid, rough, defective growth.) * Why remove or isolate small “competing” crystals in the jar? (They lower the dissolved concentration near the seed and steal material, slowing or distorting growth.) * Why do some crystals turn pale or powdery over time in open air? (Loss of water of crystallization—partial dehydration—dulls the surface.) * How can you tell your solution is near exact saturation before growth? (After seeding a pinch of powder and waiting overnight, no new crystals form on the bottom and the solution stays clear.)