Complex sentence: Riihimaki glass was a high quality glass producing company in Finland from 1910 to 1990 they made from very basic to very high quality glass ornaments which are now very highly collectible, the products this company made are all readily available via collectors websites as are their values.
Split into simpler sentences: Riihimaki glass was a high quality glass producing company in Finland from 1910 to 1990. They made from very basic to very high quality glass ornaments which are now very highly collectible, the products this company made are all readily available via collectors websites as are their values.