I am not a Swarovski expert, but every Swarovski paperweight I have seen has had a tiny etched logo somewhere on the base or near the base. I have seen other products with a similar multicolor brilliant glass with labels that said "Made in Austria" or "Made in Germany" that were not Swarovski.
The company's website at http://www.swarovski.com/Web_US/en/faq (http://www.swarovski.com/Web_US/en/faq) states the following:
"Since 1989, all genuine Swarovski products feature the Swarovski Swan logo. Pieces produced prior to this date have a different logo and in some cases, it may only be faintly visible or almost impossible to detect.
You will find the following logos on almost all Swarovski crystal and jewelry products:
Square Silver Crystal SC logo (1976 - 1988)sCs/SCS logo (Swarovski Crystal Society 1987 - present)Swan logo (1989 - present)"