Tuesday Update – Quartz

WE are now well and truly into show season. Thank you to everyone who came to see us at the Texas Mineral and Fossil Show at Dallas/Plano last weekend. The mineral collecting community in Texas is one of the best we know and we love being there for the show.

Next up is our Summer Open Weekend in the UK on June 6th and 7th. Dominantly British focused, we do also have extensive stock of European classics and a broad coverage of worldwide species for visitors to enjoy. Then, there are also our ever popular UK Mining Ventures Fluorite displays and drawers to peruse.

In the meantime, this week we focus on Quartz.

Viewed by some as a common mineral, there is no escaping its ability to produce magnificent large crystals and in a range of colours too. In amongst our selection today are colourless (Rock Crystal), brown (Smoky), purple (Amethyst), white (Milky) and red (Eisenkiesel) varieties, along with a rogue Hyalite Opal (Opal-AN) – an amorphous hydrated form of silica but which shows a mind-blowing level of fluorescence under long wave ultraviolet light.

Pure Quartz is colourless, but as with many colourless minerals very slight natural impurities can dramatically shift the colour in spectacular ways.

Quartz traditionally crystallizes as six sided (hexagonal) prisms, terminated (usually only at one end) with a six-sided pyramid. However, unusual pressure or temperature conditions during crystal growth can result in other less familiar forms. These crystallographic rarities include bipyramidal crystals, scepters, flattened tabular forms, and ‘v’-shaped twins known a Japan-Law twins.

The geological process of mountain-building, where two geological plates collide, results in some of the most spectacular crystals. Often termed ‘alpine-type’ minerals, after the European Alps where the first examples were recognized, ‘New World’ finds have been made in the Himalaya’s and surrounding mountains in Pakistan. The magnificent ‘faden’ Quartz from Dara Ismael Khan District in Pakistan is a prime example, showing how colourless tabular crystals have grown in alignment with a central white ‘thread’ giving ‘faden’ its name.

The ‘Old World’ classics from the European Alps are well-represented in this update, particularly the stunning ‘twisted’ ‘gwindel’ Smoky Quartz crystals from Switzerland.

There are so many other types of Quartz to be seen here, that I should let you get on with exploring them all. Next week, we return to an old favourite – Fluorite – but with a twist. No, not a ‘gwindel’, but all of the Fluorite specimens come from localities in the US.

Enjoy your week ahead. 

Please note: Today's featured specimens are situated at both our US and UK showrooms.