These clusters are natural and untreated. The orange color is due to a combination of iron, Hematite and Manganese coating the surface of the crystals but also present as inclusions within the crystals themselves. Lower quality material often with lots of surface damage is present on the market from Brazil, but this is some of the first high quality, natural specimens I've seen from Madagascar.
SORT
PRICE
GRADE
FOR SALE ONLY

TANGERINE (HEMATITE) QUARTZ FOR SALE

: $259 to $1,595