(optics) A doubly refracting crystal in which the index of refraction for the extraordinary ray is greater than for the ordinary ray, and the former is refracted nearer to the axis than the latter, such as quartz and ice; as opposed to negative crystal: one in which this characteristic is reversed, such as Iceland spar ...
Citrine. This crystal radiates joy and positivity. It is a light maker that imparts wonder, delight and enthusiasm in the holder. It is also a brain stimulator that will raise self-esteem and self-confidence.
In positive crystals the refractive index for e-ray is greater than refractive index for o-ray i.e. µe> µo. In negative crystals the refractive index for o-ray is greater than reflective index for e-ray i.e. µ0> µe. In positive crystals e-ray travels slower than o-ray in all directions except along the optic axis.
Negative uniaxial crystals (e.g. calcite CaCO3, ruby Al2O3) have ne < no so for these crystals, the extraordinary axis (optic axis) is the fast axis whereas for positive uniaxial crystals (e.g. quartz SiO2, sellaite (magnesium fluoride) MgF2, rutile TiO2), ne > n o and thus the extraordinary axis (optic axis) is the .. ...
negative crystal (plural negative crystals) (optics) A uniaxial crystal, such as one of calcite, in which the extraordinary wave travels faster than the ordinary wave. A crystal that contains a cavity.
A uniaxial, birefringent crystal such as calcite or ruby in which the velocity of the extraordinary ray surpasses that of the ordinary ray.
Only two minerals that are commonly used as gemstones have a uniaxial character with a positive optic sign, quartz, and zircon.
Crystal quartz is a positive uniaxial crystal. Optical grade crystal quartz features high transmittance from 200nm to 3500 nm, a high damage threshold, and excellent resistance to both scratching and chemical attacks.
It is a negative uniaxial crystal with very high birefringence, wide spectral transmission and moderate refractive index. Its extreme birefringence gives it both negative and positive relief, based on orientation.
Watch out for unknowledgeable sellers, too-good-to-be-true prices, and crystals that look too bright, glassy, clear, and perfect. Real natural crystals are cool to the touch, don't scratch easily, contain imperfections, and are usually heavier than fakes.
Calcite is a negative uniaxial crystal and mostly used as visible and near IR polarizers.
The best crystals that bring luck into the home include Green Jade, Citrine, Clear Quartz, Carnelian, Peridot, Garnet, Smoky Quartz, and Tigers Eye.
They balance the soul, alleviate anxiety, and restore confidence. This stone is used to increase wealth and vitality. Tiger's Eye brings protection against negative energy and strengthens self-worth.
Sacred Symbolism for Positive Energy: Tree of Life, Lotus, Elephant, and Spiral.
Holding crystals or placing them on your body is thought to promote physical, emotional and spiritual healing. Crystals supposedly do this by positively interacting with your body's energy field, or chakra. While some crystals are said to alleviate stress, others purportedly improve concentration or creativity.
You can wear Rose Quartz anywhere on the body and it will fill you with a healing loving light. However, as Rose Quartz is primarily a heart chakra stone, it loves to be placed in the heart space so that it can clear any blockages and ensure your heart is open and ready to receive love.
Clear quartz is the birthstone of April and therefore the zodiac signs of Aries' and Taurus' that were born in that month. It is also associated with the planet Venus, which rules Taurus and Libra. Its abilities are particularly beneficial to Aries and Scorpio.
The property that makes quartz an electronic miracle, is the fact that, when compressed or bent, it generates a charge or voltage on its surface – a phenomenon called the Piezoelectric effect.
The middle finger reflects the personality of an individual. Balance in life can be struck by wearing a gem on this finger. It helps in distinguishing right from wrong. One should wear quartz, amethyst and coral on this finger.