Technically, ‘chalcedony’ is a gemological term that applies to all varieties of quartz with a crypto-crystalline structure. However, in contemporary literature, the term ‘chalcedony’ is most commonly used in reference to very specific types of white and pale blue colored crypto-crystalline quartz, often referred to as ‘actual chalcedony’ or ‘chalcedony in the strict sense’. To minimize confusion, most other varieties of crypto-crystalline quartz are known by their own individual trade names, such as ‘agate’, ‘carnelian’ or ‘jasper’. ‘Chalcedony’ is distinguished by its transparency and hardness, lighter color, usually bluish to white or grey. The hardness of the mineral is 6.5-7 on the Mohs scale. When compared to malachite or turquoise, chalcedony has higher hardness, and is difficult to scratch domestically.

Chalcedony is a common jewellery ornamental stone and can be found on all continents. In Russia, chalcedony is mined in the Urals, Crimea and the Moscow region. Recently, rich deposits of blue chalcedony have been discovered near the Barents Sea. Other significant deposits of light, translucent and bluish chalcedony are found in Uruguay, USA, India, Madagascar, Myanmar, Mexico, Brazil and South-West Africa.

There are more than 10 subspecies of this family of stones, which differ in colour and structure. The natural colour of chalcedony is pale grey, bluish-grey, from greyish-white to milky-white and depends mainly on the number and size of micropores that scatter light. The variegated colouring is associated with iron, manganese and nickel impurities.

It is believed that as early as the Bronze Age, chalcedony was found in all territories adjacent to the Mediterranean. Since ancient times, chalcedony has been used as a jewellery and ornamental stone. Chalcedony beads dating back to the Neolithic period, ritual objects, gold jewellery from Ancient Egypt with chalcedony inserts have been discovered. Chalcedony was used and valued by the ancient Romans, Greeks, Babylonians and Assyrians. Many Native American tribes consider chalcedony sacred, and the items made of chalcedony are used in traditional ceremonies. Mentions of chalcedony products are found in the Bible.

The name ‘chalcedony’ was derived, according to most experts, from the name of the ancient city of Chalcedon, located in the Bosphorus region, now Kadıköy, Turkey.
Since antiquity, the stone has been used for jewellery and furniture inlay. Beads, rings, small figurines and cameos are carved from chalcedony. Affordable price and richness of shades allow to use stones for making interior items and souvenirs. Statuettes, vases, caskets made of chalcedony are in wide demand among buyers. Chalcedony is also used today in precision instrumentation (scale support prisms) and for chemical and pharmaceutical purposes (mortars). Most varieties of chalcedony, which are ornamental or semi-precious stones, are much better known than chalcedony itself (jasper, carnelian).

In ancient times, chalcedony was valued for its magical and healing properties. This stone was considered a symbol of love and joy. In different countries, girls did not hesitate to use the magic of this mineral to bind their beloved. Sailors believed that chalcedony would help them return to land and took a talisman made of chalcedony with them on a long voyage. Chalcedony was considered the main ‘healer of the soul’ and was used to positively influence the psycho-emotional state of a person.

The magic of the stone is closely connected with its healing properties. Lithotherapists believe that the mineral will give harmony in the soul, get rid of depression and insomnia. The stone also provides protection from the evil eye, spoilage and even gossip. During the Second World War, Soviet field surgeons used this property of chalcedony to relieve inflammation in wounds following the bioenergetic method of Professor Evgenia Badigina. A heated stone applied or placed in close proximity to a wound accelerated its healing .This property is due to the natural radioactivity of chalcedony when heated.

Chalcedony has been enchanting since ancient times with its haziness and ‘obscurity’. Chalcedony is a ‘lucky’ stone for those born in August. Chalcedony predicts them a long family life, promotes good luck in business, gets rid of melancholy attacks, protects from black envy, strengthens courage in difficult moments of life, enhances intuition and insight.

The museum Сollection section “Lapidary and Bone Craving Art Items” features a variety of chalcedony items:

On the cover: "Prince Frog" jewelry set. Luis Alberto Quispe Aparicio. The 20^th century

Fairy-tale lady fox. Manfred Wild, Germany, Idar-Oberstein. The 20^th century
Pug dog [in a box]. Russia. Circa 1920
Two Mice in the Boat. Luis Alberto Cuizpe Aparicio. The 20^th century
Mouse and a mouse cub. Luis Alberto Cuizpe Aparicio. The 20^th century
Finch on a wild rose branch. Paul Dreyer. Germany, Idar-Oberstein. The 20^th century