QUARTZ

 Quartz is a mineral composed of silicon and oxygen atoms in a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO2. Quartz is the second most abundant mineral in Earth's continental crust, behind feldspar.

Quartz crystals are chiral, and exist in two forms, the normal α-quartz and the high-temperature β-quartz. The transformation from α-quartz to β-quartz takes place abruptly at 573 °C (846 K). Since the transformation is accompanied by a significant change in volume, it can easily induce fracturing of ceramics or rocks passing through this temperature limit.

There are many different varieties of quartz, several of which are semi-precious gemstones. Since antiquity, varieties of quartz have been the most commonly used minerals in the making of jewellery and hardstone carvings, especially in Eurasia.

This post is part of the Wordless Wednesday meme,

and also part of the ABC Wednesday meme,

and also part of the Nature Notes meme.

JEWELLERY

Jewellery | ˈdʒuːəlri | (US jewelry) noun [mass noun]

Personal ornaments, such as necklaces, rings, or bracelets, that are typically made from or contain jewels and precious metal: She had silver hair and chunky gold jewellery | [as modifier]: A jewellery box.

Sapphire is a gemstone variety of the mineral corundum, an aluminium oxide (α-Al2O3). Whilst typically associated with the colour blue, sapphires can also naturally occur in a wide variety of colours such as blue, yellow, purple, orange, green colours - which are also called "fancy sapphires". "Parti sapphires" are those sapphires which show two or more colours in a single stone. The only colour which sapphire cannot be is red - as red coloured corundum is called ruby, another corundum variety. Commonly, natural sapphires are cut and polished into gemstones and worn in jewellery.

They also may be created synthetically in laboratories for industrial or decorative purposes in large crystal boules. Because of the remarkable hardness of sapphires – 9 on the Mohs scale (the third hardest mineral, after diamond at 10 and moissanite at 9.5) – sapphires are also used in some non-ornamental applications, including infrared optical components, such as in scientific instruments; high-durability windows; wristwatch crystals and movement bearings; and very thin electronic wafers, which are used as the insulating substrates of very special-purpose solid-state electronics (especially integrated circuits and GaN-based LEDs).

This post is part of the Wordless Wednesday meme,

and also part of the ABC Wednesday meme.

CRYSTALLINE

Went into a minerals and gems shop today and took some photos of some amazing crystal formations. They combine well into a mosaic.
The minerals are (clockwise from top left): Sulphur; halite; fluorite; citrine; amethyst; uvarovite; lapis lazuli; garnet.

This post is part of the Mosaic Monday meme,
and also part of the Macro Monday meme,
and also part of the Through my Lens meme,
and also part of the Seasons meme.

LAPIS TURTLE

Turtles are frequently depicted in popular culture as easygoing, patient, and wise creatures. Due to their long lifespan, slow movement, sturdiness, and wrinkled appearance, they are an emblem of longevity and stability in many cultures around the world. Turtles are regularly incorporated into human culture, with painters, photographers, poets, songwriters, and sculptors using them as subjects. They have an important role in mythologies around the world, and are often implicated in creation myths regarding the origin of the Earth. Sea turtles are a charismatic megafauna and are used as symbols of the marine environment and environmentalism.

One of my collections is little carved stone turtles, one of which made of lapis lazuli is seen here in the foreground. Lapis lazuli, or lapis for short, is a deep blue semi-precious stone prized since antiquity for its intense colour. Lapis lazuli was mined in the Sar-i Sang mines and in other mines in the Badakhshan province in northeast Afghanistan as early as the 7th millennium BC. Lapis beads have been found at neolithic burials in Mehrgarh, the Caucasus, and even as far from Afghanistan as Mauritania.

At the end of the Middle Ages, lapis lazuli began to be exported to Europe, where it was ground into powder and made into ultramarine, the finest and most expensive of all blue pigments. It was used by some of the most important artists of the Renaissance and Baroque, including Masaccio, Perugino, Titian and Vermeer, and was often reserved for the clothing of the central figures of their paintings, especially the Virgin Mary.

Today mines in northeast Afghanistan and Pakistan are still the major source of lapis lazuli. Important amounts are also produced from mines west of Lake Baikal in Russia, and in the Andes mountains in Chile. Smaller quantities are mined in Italy, Mongolia, the United States and Canada.

This post is part of the Monday Mellow Yellows meme,
and also part of the Blue Monday meme,
and also part of the Through my Lens meme,
and also part of the Seasons meme.

FRIDAY GREENS #92 - MALACHITE

Welcome to this meme active every Friday. The theme is "Friday Greens" and you can post images, art, photos where the predominant colour is GREEN!

GREEN is the colour between blue and yellow in the spectrum; coloured like grass or emeralds.

Malachite is a copper carbonate hydroxide mineral, with the formula Cu2CO3(OH)2. This opaque, green banded mineral crystallizes in the monoclinic crystal system, and most often forms botryoidal, fibrous, or stalagmitic masses, in fractures and spaces, deep underground, where the water table and hydrothermal fluids provide the means for chemical precipitation. Individual crystals are rare but do occur as slender to acicular prisms. Pseudomorphs after more tabular or blocky azurite crystals also occur.

The stone's name derives (via Latin: molochītis, Middle French: melochite, and Middle English melochites) from Greek Μολοχίτης λίθος molochitis lithos, "mallow-green stone", from μολόχη molōchē, variant of μαλάχη malāchē, "mallow". The mineral was given this name due to its resemblance to the leaves of the mallow plant.

If you take part in this meme:
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