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 is a very affordable gemstone, and all its color ranges are not expensive. It is most often confused with orange-yellow Topaz, which is very similar in color and body. Topaz is the more valuable gemstone, and dealers often sell Citrine labeled as Topaz. Several false trade names for Citrine are Madeira Topaz, Gold Topaz, and Bahia Topaz.