Up until the end of the 19th century yell sapphire was known as "oriental topaz" (only blue corundum was culled sapphire) nevertheless yellow and greenish yellow sapphires make unusual and attractive gemstones in their own right.

In Queensland and New South Wales (Australia), a greenish yellow sapphire is found that may be faceted. Similar stones occur in Thailand, and purely yellow stones in Sri Lanka, Montana (USA), and Fast Africa. Brilliant

Feldspars form in igneous and metamorphic rocks. Which type is formed depends on the temperature it forms at, and how it cools.