Ametrine 18x28mm Oval - 15-16 Inch 48hr_06252024 and this phenomenon is thought

and this phenomenon is thought to be due to impurities of yttrium or organic matter within the crystal lattice

They are all silicate minerals

the colors are naturally occurring

Most topaz grows as crystals within the veins and voids of igneous rocks

Ametrine 18x28mm Oval - 15-16 Inch 48hr_06252024 and this phenomenon is thoughtAmetrine is quartz that occurs in bands of purple and yellow. As the name suggests, it is a combination of Amethyst and Citrine. The different colored zones in the stone result from different oxidation states of iron, due to exposure to different temperatures during its formation. It is believed that Ametrine was first introduced to Europe by a conquistadors gift from Bolivia to the Spanish Queen.