In the end of 2019 I've been fortunate enough to get my hands on a wonderful combo specimen of Topaz-Smoky Quartz-Schorl from Klein Spitzkopje, Namibia. It was already great to look at - the Topaz was lustrous and transparent, the Quartz is beautifully striated on the prism faces and amongst several there's one Schorl crystal that bridges the gap between those two main crystals. However something felt a little off. Inspecting the specimen it became apparent that some iron staining creates a yellowish hue to the Topaz which I didn't like. So I prepared to snap on my gloves and goggles...

The Topaz (ID #191203) specimen is an oldtimer from the collection of a late Hungarian geologyst lady. The Topaz crystal has a chip on the backside (see the left side of the crystal on the left picture above) but it’s beautifully transparent and gemmy and grows out of a horizontally striated Smoky Quartz which is penetrated here and there by Schorl (black Tourmaline) crystals. In my opinion it’s a highly collectible material and the old label and provenance makes it very special to me. However I was a little unsatisfied with the appearance of the specimen as the Topaz seemed to have a slightly yellow hue from different angles. I’ve detected a couple of spots where patches of brown iron stains borrowed this yellowish hue to the Topaz and I figured that the relatively chemical resistant silicate combination of Topaz-Quartz-Schorl should stand the fight in a dilute solution of sodium dithionate and hydrochloric acid for a brief period of time. As you can see on the picture below the iron content of the solution caused a greenish yellow color in the solution which I was happy about as ferro- (Fe2+) and ferri (Fe3+) ions should be green and brown respectively.

After the stains have been removed extensive rinsing and soaking took place (for 48 hours). The result can be seen in the Gallery - the gorgeous and tall Topaz crystal standing proudly and transparently (and without a hue now!) on the light Smoky with those little Schorl straws. I’m very proud that I could elevate the looks of this historic piece.