Huge, transparent, gem-quality crystals are found there. Topaz has also come from the Ural Mountains of Russia, Mexico and the U.S. (Texas, Colorado and Utah). Topaz is often confused with the less valuable citrine. Topaz is a very hard gemstone but it can be split with a single blow, a trait it shares with diamond. Any Topaz labeled with a prefix name (such as Gold Topaz, Madeira Topaz, False Topaz, Brazilian Topaz, Bahia Topaz, and Citrine Topaz) is heat-treated Citrine.
Dietary collagen is available from the following sources: 1  Piscine (fish). 2  PROS: Collagen peptides from fish are considered to be superior in raising overall body collagen (Type 1) and improving skin, hair, nail, and bone quality. 3  CONS: Fish collagen peptides generally cost more than other sources of collagen.
Parvalbumin was identified as a major fish allergen, and has been well investigated. Collagen was identified as a second allergen; however, its allergenic properties remain uncharacterized. Although fish is an important staple in coastal countries, its thermostability is unknown. Therefore, we aimed to determine the thermostability of fish collagen as an allergen.