Did You already arrived to Prague? Start to think about souvenirs as soon as possible. Use e-shops, buy originals and save money and time.
Czech republic has long tradition of the glass mastership (see wiki). It started in 13th century and Czech glass is now famous worldwide. Glass making process is difficult, traditional manual, include cutting, carving. So you can say, each piece is original. But be careful! Not everything, you will see in Czech republic is crystal. It could be just simple glass, produced somewhere else imported to Czech republic.
In the European Union, labeling of „crystal“ products is regulated by Council Directive 69/493/EEC, which defines four categories, depending on the chemical composition and properties of the material. Only glass products containing at least 24% of lead oxide may be referred to as „lead crystal“. The presence of lead in crystal softens the glass and makes it more accessible for cutting and engraving. Lead increases the weight of the glass and causes the glass to diffract light.
Btw. Swarovski the founder of todays Swarovski company with crystal jewelry was born in North Bohemia during the time of Austrian Empire (see wiki).
Some of e-shops, they sell and mostly do curving/cutting of the crystal: