From mid-2021, newsletter articles are no longer posted separately here. Interested readers should scan through the newsletter headings under the ‘Newsletters’ tab.

FACETIPS – A GEM CUTTER’S NOTEBOOK

by
Duncan Miller


The faceting articles published over the past few years in the Mineral Chatter have been compiled into a single 128 page document, available for download for those interested in saving all the articles together. To download the pdf file click here.

A 29,18 ct cuprite from Onganja, Namibia, cut by Duncan Miller and now in a private collection in Germany.


Browsing Archive: February, 2021

THE MOST DIFFICULT JIGSAW PUZZLE OF ALL TIME

Posted by Site Moderator Webmaster on Wednesday, February 24, 2021,
by
Duncan Miller

Imagine a jigsaw puzzle the size of the Earth, with most of the pieces missing. And those that aren’t missing are moving around all the time. This is the task that confronts some ambitious geologists. It is important because it explains why there are oceans and mountain chains, and why we may find rocks of similar ages and composition on far-flung continents. It also satisfies human scientific curiosity, and keeps some people employed and off the streets.

Until the mid-1960s...


Continue reading ...
 

Botryoidal Minerals: A Colourful Trip Around the Mineral Kingdom

Posted by Site Moderator Webmaster on Wednesday, February 24, 2021, In : Mineralogy 

by
Peter Rosewarne

Introduction

My previous MinChat article on fluorite described a colourful trip around the world. In this article we take a colourful trip around the mineral kingdom, using minerals with a botryoidal habit as the guide. The idea came from the supplement to The Mineral Record of January-February 2020 on Mineral Collectors in Arizona, with the focus of one of the collectors being on botryoidal mineral specimens. The term botryoidal is derived from the Greek word botryios or â€...


Continue reading ...
 
 

Make a free website with Yola