The stone that made me a mineral collector and got me hooked in this field was Fluorite, a school trip to the famous Blue John Fluorite mine in Derbyshire, England when I was around 10 years old lit a fire within me that has been burning ever since. I probably own more Blue John Fluorite than I do of any other stone in my collection.

Blue John is a semi-precious gemstone considered to be one of the rarest minerals in the world, found only within the Treak Cliff Cavern, Castleton, Derbyshire Peak District National Park. Treasured as one of the world’s rarest minerals, each piece of Derbyshire Blue John stone is unique and varied in colour, common veining makes every piece of Blue John jewellery truly special.

Blue John had 14 distinct variants of colour and I had an example of every piece in my collection, however in 2015 the BBC announced there had been a new discovery. After thinking that this chapter of my collection was closed, I was hooked and I took a drive out to Blue John.

Mr Ridley, who manages Treak Cliff Cavern, said he tried out the new saw near the tourist route.

“Having spotted a small amount of crystallisation near the handrail it was just an easy and convenient place to see how well the saw would cut…

“I couldn’t believe my eyes when within a few minutes I had uncovered a substantial deposit of Blue John unlike any other vein I had ever seen before.”

Each vein has its own colour and banding of blue, purple, yellow and white. Historically, there have been 14 distinct veins of Blue John including Millers Vein, Treak Cliff Blue Vein, 5 Vein, 12 Vein and Old Tor Vein.

The Ridley Vein has now entered the record books as variant number 15. I’m lucky enough to say that it has also entered my collection as well.

This year has seen deposits uncovered in China that has challenged Blue Johns long held dominance as the premium source for gem quality Fluorite. The colours that entered the market in 2016 sent shockwaves through the industry that shook the very foundations of Blue John.

My extensive mineral collection started with Blue John, I consider myself an authority on Blue John material and even I have been humbled by the myriad of exceptional colours from these Chinese mines.

There have been three distinct varieties that have appeared on the market in small parcels, these have been snapped up by collectors and currently the price is so high that I’m priced out of owning clean stones.

The rarest variety is the Zebra fluorite which mixes a teal/ sea foam colour with an exceptional saturation of Siberian purple. I’ve only ever seen two cut stones that possess this colour.

I was privy to an offering of a colour change parcel which contained 18 stones. These stones exhibited the strongest colour change I’ve seen in any stone, a London blue by day, hot pink by night. The locals call this ‘The Baiyang Stone’ after a lake that is blue for half the year but in spring time turns pink because the lotus flowers break the surface and blossom in vast numbers.

The same dealer also presented me with a slightly larger parcel of teal stones, a colour I’ve never seen in gem quality fluorite with a vivid saturation which was quickly dubbed ‘Tuscon Green’ because it was the talk of Tuscon on opening day of the world gemstone trade show.

Unfortunately a year later none of these stones have resurfaced at Tuscon which shows how fleeting these exceptional discoveries can be and solidifies the mantra I live by – “If you see it and love it, don’t let it get away”