Chalcedony is a microcrystalline type of quartz occurring in several different forms including Agate & Onyx.. Chalcedony assists in helping One's Confidence & Willpower. Enhance the sense of Self Worth.
Also helps with Mental Clarity, Communication, Joy, Happiness, Optimism, Harmony, Inner Stability. Source : naturalhealinggems
Yellow Calcite is associated with the solar plexus, self-confidence and hope. It is said to be effective at clearing out old energy patterns and increasing personal motivation and drive. Yellow Calcite clears accumulated self-doubt, giving you the opportunity for a clean emotional slate.
It is also known as a mind stone as it heightens mental discernment and analysis, increases memory and the ability to learn quickly and efficiently, great to have on your desk during revision/tests etc. Calcite is by far the best stone for anyone studying.
These pieces are very bright yellow and makes one feel so cheery.
Yellow- Yellow Calcite White & off White - Chalcedony
Brownish & Black- Agate & Onyx
** these are natural crystals may have imperfections
From Brazil