4 Pack K9 Optical Crystal Photography Prism Set, Include 55mm Crystal Ball, 50mm Crystal Cube, 50mm Triangular Prism, 60mm Optical Pyramid with Gift Box& Wipe Cloth for Teaching, Playing, Photography

I like the look of these glass shapes - the glass is very clear. If I was to complain about anything, it would be the small size of the prism shape - it's not of the same proportion of the other three objects. Happy with my purchase.

Price was good, the glass is nice and clear, and heavy. It showed up quickly and in good order...I wish I had more time to type, but the sun is out so I gotta go play with them and my camera!

I like this set, only issue is a bubble inside the triangular prism - which is a one point demerit here.Otherwise, set cam with a nice case to store them in. Really cant complain sans the bubble.

No problems with product. Shipping was fine. Product arrived well protected.

I bought those to teach my 6-year-old daughter the principals of light and how rainbows are formed. The two triangular ones create rainbows with a beam of sunlight shining through the windows, she had plenty of fun with it.As a bonus, the glass sphere rolls on our hardwood floor quite smoothly, and she had fun with that as well :)She then used the square block to build a frozen Elsa castle with the rest of her legos. I consider this "toy" is money well spent compared to the plastic ones that needs to be thrown away often.

All crystals are came without defects. For someone who says "it's not real prism": Any glass can refract light because it is a transparent material with a different refractive index than air. You need to rotate prism. Special angle is required to get rainbow effect.

I bought these for a science demonstration on light refraction (white light getting split into the rainbow) however I was disappointed in the rainbow these were able to generate. When these arrived, it was already dark outside so I couldn't initially test with natural sunlight. I tested all of the prisms with various light sources (LED flashlight, incandescent work light, LED ceiling light, Incandescent ceiling light, LED chandelier, brighter LED flashlights, etc...) and was never able to get anything other than bright white spots indicating that it was reflecting light rather than refracting it.I then tried the some of the same light sources with a small prism that hangs in the window and casts rainbows around the room when in sunlight. Unfortunately we also failed to create rainbows with it, so we figured you needed natural sunlight.The next day I waited until the prism we already had was casting its rainbows and then tried these prisms right next to it in the natural sunlight and was eventually able to see a faint rainbow occasionally. However, while the small decorative prism we had cast rainbows all around the room (due to the cut of the glass) that were easily visible and had good definition between the colors, these prisms were at best able to cast a faint rainbow is a very narrow line. I'd estimate the total rainbow to be crammed into a line roughly 1-2mm wide and usually only a few inches long at best. Not exactly a great science demonstration for kids.I went ahead and did the science demonstration for the scout troop later that night and using a small LED flashlight I was able to recreate those tiny rainbows for them, but again was never able to get them to be very bright nor more than about 1mm wide. Multiple and adults and kids all tried to generate a good rainbow and all were unable to (so, hurray, it's not just me failing at prism-ing?)One of the prisms also had a manufacturing defect with a roughly 2mm wide air bubble in the glass/acrylic. I don't think this had a significant effect on the refraction though.Pros: Other than the one air bubble, the prisms were very clear and looked well made and polished. The prisms come with a cleaning cloth similar to an eye glass cleaning cloth and were well packaged. They looked good, we just couldn't figure out how to actually make them "prism".

Bought these to teach my child about prisms. They chip easy and their storage box is not sturdy at all. The prisms don’t cast a full rainbow like I wanted, but my child loves them, and that’s what matters. Every time the sun shines in they go grab the prisms to make the light refract. The price point is good for what It is. Don’t expect to use these professionally for photography or anything and don’t let your child play with them unsupervised because they do chip pretty easily.