MAGNETITE Jaschandrika Rana, group 22. Scientific adviser is Svetlana Nakonechnaya

TEKTITE

Kunwardeep Singh, group22. Scientific advisor is Svetlana Nakonechnaya

1. Splash-form Tektites

2. Aerodynamically Shaped Tektites

3. MuongNong-type Tektite

Majority of known tektites occur only within four geographically extensive strewn fields. The ages of tektite from the four strewnfields have been determined using radiometric dating methods. The age of moldavites, a type of tektite found in Czech Republic, was determined to be 14 million years, which agrees well with the age determined for the NordlingerRiesCrator. Although tektites are superficially similar to some terrestrial volcanic glasses, they have unusual distictive physical characteristics that distinguish them from such glasses. First, they are completely glassy and lack any microlites or phenocrysts, unlike terrestrial volcanic glasses. Second, although high in silica, the bulk chemical and isotopic composition of tektite is closer to those of shales and similar sedimentary rocks and quite different from the bulk chemical and isotopic composition of terrestrial volcanic glasses. They have a chunky, blocky appearance, exhibits a layered structure with abundant vesicles and contain mineral inclusions such as zircon, baddeleyite, chromite, rutile, corundum, cristobalite and coesite. Tektites have been worn as talismans for fertility on all levels. This stone balances male-female energies within the personality. Tektite helps us to release undesirable experiences, remembering lessons learned and on certaining on those things that are conductive to spiritual growth, takes you deep into the heart of a matter, promotion insight into the true cause and necessary action. Tektite is also used in healing, as it reduces fever, aids the capillaries and circulation. It prevents the transmission of diseases. Certain types of tektite have been used for psychic surgery.

AQUAMARINE

Shubham, group 24. Scientific adviser is Tatyana Tishakova

Its chemical formula is Be₃Al₂SiO₆, its composition is Beryllium Aluminum Silicate, its refractive index is 1.57–1.58, its crystal system is hexagonal.

Aquamarine is the most popular light-blue gemstone, and is extensively used in jewelry. Rings, earrings, and bracelets are made from Aquamarine, and it is especially important as a pendant stone, with fairly large pendants being faceted from Aquamarine. Very large display gems, that are too large for standard jewelry use, are occasionally faceted for exclusive collectors. Less transparent stones may be cut into cabochons. Quality Aquamarine crystals are also highly valued by collectors in their natural form.

Its medical uses are that its helps in decreasing toothaches, insomnia, sea sickness. The stone can also aid in digestion, cure throat problem & reduce drug dependence.

Its largest producer is Brazil. It is also found in Pakistan, Burma, Russia, China, Nambia, Kenya, United states.

CALCITE

Abinash Swain, group 24. Scientific adviser is Tatyana Tishakova

• Strunz – 05.AB.05

• Crystal – Trigonal 32/m

• Unit Cell – A=4.9896(2)A, C=17.0610(2)A, Z=6

Calcite is a carbonate mineral and the most stable polymer of calcium carbonate. The other polymers are minerals, aragonite and vaterite. Argonnite will change to calcite at 380-470 degree celcious and varerite is even less stable.

It is discovered by scientist Rasmus Bartholin in 1669. At a wavelength of 590 nm calcite has ordinary and extra-ordinary refractive indices of 1.658 and 1.486 respectively. Single calacitecrystal display an optical property called brifringence. This strong brifringence caused of objects viewed through clear piece of calcite to appear to doubled the birefringent.

High grade optical calcite was used in world war II for gun sights. Specifically in bomb sights and anti air craft weaponary. Also experiments have been conducted to use calcite for a clock of unvisibility.

It is used for relieving backaches and to increase physical strength, improving the health of teeth and eyes, this healing crystal is considerd as a good general purpose healer. Used in conjustion with massage to spread its healing and cleansing energy through out the body by removing negeative energy. Holding calcite, or placing it at various chakra points, energizes the bodies natural electrical system.