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The UV-sensitivity of natural citrine further indicates that its color is not caused solely by trace elements. [2] Most citrine on the market is heat-treated amethyst or smoky quartz. Amethyst loses its natural violet color when heated to above 200-300°C and turns a color that resembles natural citrine, but is often more reddish or brownish. [9]
As of 2020, the most expensive non-synthetic element by both mass and volume is rhodium. It is followed by caesium, iridium and palladium by mass and iridium, gold and platinum by volume. Carbon in the form of diamond can be more expensive than rhodium. Per-kilogram prices of some synthetic radioisotopes range to trillions of dollars.
This is a list of minerals which have Wikipedia articles. Minerals are distinguished by various chemical and physical properties. Differences in chemical composition and crystal structure distinguish the various species .
A chemical element, often simply called an element, is a type of atom which has a specific number of protons in its atomic nucleus (i.e., a specific atomic number, or Z). [ 1 ] The definitive visualisation of all 118 elements is the periodic table of the elements , whose history along the principles of the periodic law was one of the founding ...
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However, in real materials there are deviations from this in some metals where the unit cell is distorted in one direction but the structure still retains the hcp space group—remarkable all the elements have a ratio of lattice parameters c/a < 1.633 (best are Mg and Co and worst Be with c/a ~ 1.568).
Evidence suggests the color of citrine is linked to the presence of aluminum-based color centers in its crystal structure, similar to those of smoky quartz. Both smoky quartz and citrine are dichroic in polarized light and will fade when heated sufficiently or exposed to UV light. They may occur together in the same crystal as “smoky citrine.”
Ametrine, as its name suggests, is commonly believed to be a combination of citrine and amethyst in the same crystal. However, sources do not agree that the yellow-orange quartz component of ametrine may properly be called citrine.