Natural topaz comes in many colors but mostly shades of yellow or clear. That’s probably why it is grouped with citrine as the birthstone for November. The most valuable of the natural topaz is “Imperial topaz” a bright yellow to gold-brown color. It is rare and often confused with citrine (always buy from reputable dealers!). Often imperial topaz fades in the sun; with extended exposure the gold tones fade to plain (at least much less colorful) clear topaz. More commonl

Sunset Crater was too hot! There were no trees (or bushes, or grass), too much dust and I had a rock in my shoe. I was walking around the base of a giant pile of bits of red cinder of the sort I had previously encountered in xeriscape gardens looking for olivine. Even the breeze was hot. And worst of all, I didn’t even know what I was looking for. Olivine? We had been informed the bright orange and red cinder cone had bright green gemstones and then our class had been tu

I have a confession to make. As a geologist, some part of my psyche mandates that I love rocks. ALL rocks, ALL minerals. In kindergarten I was a magpie, attracted to rocks, gemstones and generally anything colorful and shiny. (My collection of shiny pennies and pebbles was something to behold!) And as a child I hated rubies. It all started (as so many things do) with childhood expectations: Like the one that says you will get on a bicycle and, like magic, ride down the

I’ve been watching the CNN live feed of the lava fountain at Kilauea on and off all day and I noticed that the black rock on the edge keeps changing shape. Why? And where is it going? To answer this question, I have to talk a little about how eruptions like the one currently happening in Hawaii evolve over time. I’ll include diagrams, some photos from the USGS and some photos from Craters of the Moon National Monument in Idaho for comparison. Fissure flows like those at Ki

There is something otherworldly and un-nerving about the Black Canyon. It is so named because the bottom of the narrow chasm gets so little light. Black Canyon is not as deep as the Grand Canyon, nor as wide but it makes just as deep an impression. The rocks are hard and so the Gunnison River snakes around in the depths of the canyon, surrounded by sheer walls of black Proterozoic metamorphic rocks and wiggling stripes of igneous rock. Our field trip vans pulled into the B

Ever since I decided to attach a blog to my website, I’ve had this desire to write about birthstones. It seems perfect. Pretty-shiny gemstones, human interest, geology, geochemistry, all the drama of international finance and trade wars! There is always one problem: what to write about. Last month, I thought I would write about diamonds. That went well…. “Mom, I’m going to write about diamonds this time!” “Great, what are you going to say about them?” “Well, I was thinki

Hi, I’m Sumire. Welcome to the blog of Sumire Designs! Writing the very first blog post in my very first blog is tough. I’ve been waffling about what to say for weeks…. Finally, one of my family members said, “Just post something! Anything!” So this is my introduction to my website, shop and blog! I’ll write about a little of everything here - my interests are many. First let me tell you a little about me…. I am a geologist: my thesis is about trace element geochemistr