It’s really hard to tell just by looking. The acrylic ones are really nice, some of them anyway, and look just like glass. The easiest way to tell the difference is the weight. Acrylic beads are much lighter-weight than are glass ones. Another simple test is temperature. Glass beads, when you first pick them up, will be much cooler than acrylic ones. After being in your hand for a few seconds, glass beads will warm up a bit. The acrylic ones don’t change temperature as quickly, either.
Give them the squeak test. Glass will squeak when forced together in the palm of your hand the same way glass marbles do. Acrylic does not have the same properties to make that tell tale squeak.
Weigh them – acrylic is lighter.
Try burning one – acrylic will burn
Glass is harder than acrylic will scratch a plastic sheet if dragged over it.
settling test in a viscous liquid, glass will settle quicker due to its weight
if you have a container of each, try smelling them, acrylic as its own distinctive smell
refractive index is different but may be difficult to measure
acrylic will soften if placed in a suitable solvent
It’s really hard to tell just by looking. The acrylic ones are really nice, some of them anyway, and look just like glass. The easiest way to tell the difference is the weight. Acrylic beads are much lighter-weight than are glass ones. Another simple test is temperature. Glass beads, when you first pick them up, will be much cooler than acrylic ones. After being in your hand for a few seconds, glass beads will warm up a bit. The acrylic ones don’t change temperature as quickly, either.
Give them the squeak test. Glass will squeak when forced together in the palm of your hand the same way glass marbles do. Acrylic does not have the same properties to make that tell tale squeak.
Differences to tell between the 2 could be:
Weigh them – acrylic is lighter.
Try burning one – acrylic will burn
Glass is harder than acrylic will scratch a plastic sheet if dragged over it.
settling test in a viscous liquid, glass will settle quicker due to its weight
if you have a container of each, try smelling them, acrylic as its own distinctive smell
refractive index is different but may be difficult to measure
acrylic will soften if placed in a suitable solvent
Hope these help
Click them against your teeth! You will quickly be able to tell glass from any type of acrylic or plastic.