Most Total Time Spent in Space. Soviet cosmonaut Sergei Krikalev holds this record, with a little more than 803 days accrued over six spaceflights. That's more than two years and two months spent zipping around the Earth.
Natural citrines are rare. Most commercial citrine is heat-treated amethyst or smoky quartz. Because the color is now caused by finely distributed iron minerals (mostly hematite and goethite), heated amethyst is not a citrine in the strict sense.Quartz colored by inclusions of any kind is not called a citrine.atural citrines are rare. Most commercial citrine is heat-treated amethyst or smoky quartz. Because the color is now caused by finely distributed iron minerals (mostly hematite and goethite), heated amethyst is not a citrine in the strict sense. Quartz colored by inclusions of any kind is not called a citrine.
Citrine Jewelry Add sparkling citrine jewelry to your collection. The brilliant glow of these gemstones accentuates just about any outfit or style. From earrings and necklaces to bracelets and rings, youâll find a great piece for your rotation of fine jewelry. Complement an elegant ensemble with citrine earrings. Studs or teardrop styles look gorgeous with diamond accents. Choose from yellow gold or white gold settings to play up the luster of these gemstones.