crystal making - seeded vs. non-seeded string
Posted: Fri Apr 13, 2012 12:44 pm
We are doing a seeded vs. non-seeded string crystal making project for the science fair, using borax, salt and sugar, similar to the experiment on this site.
So far results are mixed. Borax grows wildly, quickly and the seeded strings may be more uniform but the unseeded yield slightly larger amounts of crystal. The jar bottoms are coated with borax crystals with both seeded and unseeded strings in the borax solution. With salt, the seeded strings yield nothing and the unseeded strings are growing crystals. This has happened with 2 trials. With sugar, the crystals grow more uniformly on the seeded strings and also seem more dense. But the non seeded catch up and may even surpass the seeded strings. We are on days 1 and 2 of 2 trials. It seems that with seeded strings some of the seeding falls to the bottom of the jar and causes growth "off the string" and in the jar, which can account for why the non-seeded grow as large or larger "on the string". Any thoughts about this? We are using a food-safe cotton meat-tying string. It has texture and small crystals find the little cotton "hairs" and adhere to it well. Is it possible that seeding the string with salt in particular makes the surface of the string smooth and crystals won't adhere to it? Thoughts? Nicole and her mom.
So far results are mixed. Borax grows wildly, quickly and the seeded strings may be more uniform but the unseeded yield slightly larger amounts of crystal. The jar bottoms are coated with borax crystals with both seeded and unseeded strings in the borax solution. With salt, the seeded strings yield nothing and the unseeded strings are growing crystals. This has happened with 2 trials. With sugar, the crystals grow more uniformly on the seeded strings and also seem more dense. But the non seeded catch up and may even surpass the seeded strings. We are on days 1 and 2 of 2 trials. It seems that with seeded strings some of the seeding falls to the bottom of the jar and causes growth "off the string" and in the jar, which can account for why the non-seeded grow as large or larger "on the string". Any thoughts about this? We are using a food-safe cotton meat-tying string. It has texture and small crystals find the little cotton "hairs" and adhere to it well. Is it possible that seeding the string with salt in particular makes the surface of the string smooth and crystals won't adhere to it? Thoughts? Nicole and her mom.
