A stone that once grew organically could be a description of just a few minerals, petrified wood is one of them, also known as fossil wood, agatised wood...
Although found in several locations around the world, USA, Europe, Japan, Australia our story is about petrified wood from Madagascar which is often prized as the source of the better colour examples with popular vivid reds and greens.
I have already covered the exotic Desert Roses that are crystals of Gypsum that have incorporated sand grains into their flower like structure, see issue 59, Spring 2013.
The mineral Gypsum is both a practical mineral and a beautiful one, it often forms as slender wonderful crystals in deserts and mines, we all use this mineral in our every day lives in everything from toothpaste to plaster on the walls of our homes and offices.
by Ruby Loveridge
“October’s child is born for woe, And life’s vicissitudes must know, But lay an opal on her breast, And hope will lull those woes to rest.”
The first recorded name of the Opal was given by the Ancient Romans, who referred to the stone as ‘Opalus’, which means, ‘precious stone’. Later on the Greeks soon renamed the stone ‘Opallos’, meaning ‘to see a change (of colour)’.
by Dave Gibson
Opal was known to the Aztecs by the name Vitzitziltecpa which means hummingbird stone, due to its similarity to the bright iridescent colours of the birds plumage. The original mining locations were lost during the Spanish conquest. They were rediscovered sometime in the early 1800's in the state of Queretaro, some 130 miles North West of the Mexico City.
By John Betterton
Sulfur, S, occurs at about 260 ppm in the Earth’s crust and its various minerals are very diverse and some are abundant.
World production currently stands at exceeds 70,000,000 tonnes per year. Most of it is recovered from fossil fuels from leading nations such as the USA, Canada, Russia, China, Saudi Arabia etc.
The industrial uses for sulfur are vast and range from vulcanisation of rubber, sulphuric acid, sulfur trioxide, numerous other chemical and pharmaceutical compounds, fertilizers, rust removal, explosives, fuels, paints, bleach papers, detergents, many organic compounds etc.
rubidium and gallium minerals
By John Betterton
Rubidium and Gallium are among the rarest of metals in the Earth’s crust
Rubidium (Rb) and gallium (Ga) are among the rarest of metals in the Earth’s crust with elemental abundances of about ...
by Barry Taylor
My all time favourite minerals are the spectacular Zeolites from the Deccan Plateau region in India, this is a flood Basalt deposit that formed... over several million years.
This is one of the largest volcanic features on earth and covers 163,000 square miles to a depth of 6,500 ft, the area covered by lava incorporates eight seperate states of India and covers a large part of the country.
Stilbite and Heulandite by Barry Taylor
This beautiful Zeolite is also known as Wheat Sheaf Ore due to its distinctive crystal shape when twinned, looking like the stooks of wheat,
fresh in the fields when hand gathered. Stlibite is commonly found ...
"The gleaming Ruby
should adorn all those who in July are born,
for thus they’ll be exempt and free,
from lover’s doubts and anxiety.”
A Ruby is a pink to blood red colored gemstone, and a variety of the mineral corundum (aluminum oxide), though other colours of gem quality corundum are called Sapphires.
Most texts consider Ruby to be the birthstone of July which means it falls into the Zodiac sign of Cancer or Capricorn.
by Patrick Gaffikin
Go, my sons, buy stout shoes, climb the mountains, search the valleys, the deserts, the sea shores, and the deep recesses of the earth. Mark well the various kind of minerals, note their properties and their mode of origin....
Petrus Severinus, a Danish physician. (1542-1602)
What are minerals?
A mineral is a naturally occurring inorganic solid with a definite chemical composition.
This very attractive mineral can often look similar to crystals of quartz, the crystals are found in association with Zeolites which are a confusing group that I will be looking at in detail later. Crystals of Apophyllite ...
I have always been fascinated by the beautiful natural art that is captured in polished slices of Agate. Some Agates are opaque and beautifully banded, whilst others are translucent in thin slices, occasionally some react in strange ways to transmitted light.
Stunningly beautiful natural Agates have a magical charm of their own, all the pictures ...
by John Betterton
The plentiful cryptocrystalline/microcrystalline varieties of quartz are described in this article. Cryptocrystalline/microcrystalline quartz is composed of minute crystals that are made up of twisted, very fine intergrown crystals of quartz with a variable fibre-like morphology. They also contain microscopic pores, fluids and or...
Fluorine, F, is one of the more reactive non-metals and is quite abundant with a crustal abundance of around 950 ppm.
World production is currently about 6 million tonnes with China, Mexico, Mongolia and South Africa the major supplies.
by Barry Taylor
I have written various articles over the years about the beauty to be found in Quartz Crystals as well as the wonderful magical inclusions that have so captivated my mind, here I revisit a few of my all time favourites together with some new images.
by John Betterton
Iridium, Ir, osmium, Os and ruthenium, Ru are among the rarest of the elements and thus they produce few minerals. Hence we treat them together.
Iridium is one of least common metals with a crustal abundance of about 3 parts per trillion. Most of this metal is extracted from the by-product of nickel refining. Canada is the main producer along with South Africa and Russia. About 3 tonnes are produced each year.
The magazine has regular featured mineral article most issues, everything from creation, abundance to crystal lattice and structure.
Rocks, stones crystals, gems all formed from minerals or the combination of, made up of atoms and electrons and formed with distinctive characteristics, shapes and structures.
Often formed by volcanic activity, magma, compression and evaporation of water.
Several known structures are seen including cubic, tetragonal,hexagonal,monoclinic, triclinic, orthorhombic.
The magazine always has a range of suppliers that stock minerals both common and hard to find.
by John Pearce
Microminerals are very small mineral specimens that require some magnification and illumination to appreciate them and see the crystals in detail. Not much magnification is needed, a 10 times or 20 times hand lens could do it, but a stereomicroscope with a magnification of 10 to 60 times would be even better. Small minerals with crystals of 1 to 2mm can barely be seen with the naked eye, but can look wonderful under a microscope (see Fig. 1). Sheer magic!
agates in sedimentary environments
Let us start by dispelling the myth, there is no such a thing as a sedimentary Agate, they do not exist as such, look-alike agates in a sedimentary environment form by different processes.
The rocks that appear on casual glance to have Agate like features are just look-alikes, certain ...
The Sedgwick Museum is part of the Department of Earth Sciences,University of Cambridge. The museum was founded in 1728 when Dr John Woodward bequeathed the geological part of his enormous collection to the university.
WOODWARD'S BEQUEST is still almost intact and can be seen in the present museum in its original walnut veneered cabinets. The main collections of the museum are divided into three: fossils, rocks and minerals. What follows is a brief history and description of the last two.
The rock collection has over 150,000 specimens from all over the world.
By John Betterton
Thorium, Th, is a relatively rare metal in the Earth’s crust with an average abundance of roughly 5.6 ppm. World production currently stands at around 5000 tonnes per year with Brazil, India, Turkey, Australia and the USA the major produces. The monazite group of phosphate minerals are the current source of the world’s supply of this element. Most of the older uses for this element have been discontinued due to its radioactivity and is still used gas tungsten arc welding.